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Techniques of Crime Scene Investigation
Marshall
311
Other
Post-Graduate
10/18/2021

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Term
What is evidence?
Definition
something legally submitted to a competent trier of fact as a means of ascertaining the truth of any alleged matter under investigation.
Term
What are the two types of evidence?
Definition
testimonial and physical
Term
What is physical evidence?
Definition
is any type of evidence with an objective existence, that is, anything with size, shape, and dimension.
Term
What is testimonial evidence?
Definition
evidence given in the form of statements made under oath, usually in response to questioning.
Term
Physical evidence may also be considered what?
Definition
direct (evidence that supports a conclusion of face without inference) or circumstantial ( evidence that requires inference to connect it to a conclusion of fact)
Term
Physical evidence may be more reliable than ________.
Definition
eyewitnesses testimony
Term
What are several things physical evidence can do?
Definition
1. Physical evidence can place the suspect in contact with the victim or with the scene.
2. It can establish the identity of person associated with the crime.
3. can exonerate the innocent.
4. Corroborate victim testimony
Term
What has the CSI effect led to?
Definition
it has made jurors expect, even demanded, physical evidence in a trial.
Term
What is a second factor unrelated to the CSI effect, that has biased the publics notion of the role of physical evidence?
Definition
science and technology are perceived by most of the public to be unbiased and not subject to manipulation.
Term
What is negative evidence?
Definition
the absence of physical evidence-may provide useful information and even stop defense arguments at the time of trial.
Term
What is an inaccurate assumption made by some investigators in regards to physical evidence?
Definition
they may think that every item of PE can be directly associated to a specific person, place, or thing, and believe that is is possible to link that evince to a unique source.
Term
The majority of physical evidence found at a crime scene can only be _________.
Definition
Classified
Term
What does the classification of evidence mean?
Definition
Items of evidence that share a common source, that can be placed into generalized groups with other items having the same properties or "class characteristics."
Term
Historically when sufficient markings are present on pattern evidence, practitioners would do ________.
Definition
offer conclusive opinions that the known and questioned item came from a common source to a reasonable degree of scientific certainty.
Term
What does DNA testing use?
Definition
the statistical occurrence of discrete pieces of genetic material or alleles.
Term
What are the legal and scientific issues surrounding the proper handling of physical evidence?
Definition
proper techniques of collection and preservation of physical evidence.
Term
What should be considered before any evidence is seized?
Definition
A search warrant or a court order should always be considered.
Term
What does fruit of the poison tree state?
Definition
failure to secure a search warrant or other appropriate legal action, may render evidence seized inadmissible. Additionally, any subsequent information obtained from this search may also be deemed inadmissible
Term
What must be demonstrated to prove the integrity of physical evidence has been maintained?
Definition
A proper chain of custom, which shows who had contact with the evidence, at what time, under what circumstances, and what changes if any were made to the evidence.
Term
What will the court require in regards to the validity of physical evidence?
Definition
the court will require proof that the evidence collected during the investigation and the evidence submitted to the court are one and the same.
Term
What is a general rule regarding how much evidence material to collect?
Definition
as much material as is reasonable possible to collect should be taken
Term
What is a second general rule in regards to how much material should be collected?
Definition
more is better than less, it may be easier to explain why you did collect something as opposed to why you did not.
Term
What are examples of of exemplars?
Definition
blood samples or buccal swabs from a victim and a subject
a known paint sample from a questioned vehicle.
Term
What is a good practice in regards to the collection of very small items of evidence?
Definition
double-wrap them. first fold them into a pharmacist fold, then place them into an envelop.
Term
What is an example of how to label potentially hazardous items going to the lab?
Definition
biohazard stickers.
Term
What is an expert witness and when may they be utilized?
Definition
expert witnesses are those individuals whom by their specialized training and skills may testify in court to explain and interpret scientific evidence to juries as well as offer their opinion based not eh evidence. They may be used when the subject of the testimony is beyond the experience and knowledge of ordinary laypeople.
Term
What are two factors of the professional police organization that ensure the argument of police bias is not true?
Definition
the integrity of the professional and the organization
Term
What is ASLDC and what do they mandate?
Definition
The American Society of Crime Laboratory Directors and they mandated a code of professional practices, known as the Guidelines for Forensic Laboratory Management Practices.
Term
Why are forensic practitioners sometimes called to court?
Definition
to testify as an expert witness.
Term
In regards to your testimony, do you have to answer yes or no?
Definition
No, you should be allowed to explain your rational.
Term
It is _______ to state you are not qualified to answer some questions.
Definition
acceptable
Term
During your testimony be cautious of questions such as _____ or ______ which have the ability to box you into a corner.
Definition
is it possible that or is it fair to say
Term
What is the final element in crime scene investigations?
Definition
Teamwork
Term
Each element of the criminal investigation must work _______.
Definition
cooperatively
Term
What is the IAI
Definition
The International Association for Identification
Term
Crime scenes are ______ and ______ changing environments.
Definition
dynamic and rapidly
Term
What is a major task of the first officer on the scene?
Definition
to protect the crime scene
Term
To a great extent the success of an investigation depends on what?
Definition
Th reactions and steps taken by the first officer to arrive on the scene.
Term
The notion of an individual coming into contact with a scene and changing it in some way is known as ______.
Definition
Locard exchange principle named after the French forensic scientist, Edmond Locard.
Term
What is a means for those involved in the investigation to minimize the loss of information?
Definition
thorough, detailed contemporaneous note take and recording significant as well as mundane observations at the time they are noticed.
Term
While protecting the scene is important, what is a critical first step the officer must take upon arrival?
Definition
render the scene safe
Term
After securing the scene the officer should attempt to form what?
Definition
an estimate of the situation, i.e. what happened here. This should be done as quickly as possible.
Term
What are several fleeting details the first officer should note as early as possible?
Definition
condition of doors, windows, lights, shades, odors, signs of activity, date/time indicators, messages on an answering machine, etc.
Term
What is rigor, livor, and algor mortis?
Definition
Rigor: stiffening of muscles after death due to a loss of ATP. Rigor mortis typically begins after about 3 hours of death and reaches maximum stiffness after about 12 hours and gradually dissipates after about 72 hours.

Livor: postmortem settling of the blood to the lower portions of the body.

Algor: postmortem cooling of the body.
Term
What is the general rule regarding firearms and ammunition found at a scene?
Definition
They should be left untouched until investigating personnel arrive on scene.
Term
What are other items the first officer on scene should attend to?
Definition
1. write down names of witnesses and other persons who entered the scene.
2. note who was at the scene upon arrival
3. establish the basic facts.
4. Keep suspect and witnesses separated
5. Instruct witnesses not to discuss the events.
6. Do not discuss the crime with witnesses or bystanders
7. Listen attentively, but unobtrusively
8. Protect evidence that is in danger of being destroyed
Term
If a weapon must be moved by an officer, how should it be done?
Definition
grasp the checkered surface of the grips with two gloved fingers.
Term
What are two items that may reveal the direction of the shot and possibly the location of the assailant?
Definition
the position of bullets and cartridge cases.
Term
what are several objectives of the crime scene investigation?
Definition
1. reconstruct the incident
2. ascertain the sequence of events
3. determine the mode of operation
4. uncover a motive
5. discover what property was stolen
6. find out the extent of criminal activity .
7. determine the subject
8. recover physical evidence
9. identify victims
Term
What is the duty of the crime scene investigators?
Definition
gather all evidence available at the scene
Term
The crime scene investigator like the first responders should approach the scene how?
Definition
calmly and deliberately
Term
What is a good rule of thumb in regards to crime scene processing?
Definition
it is better to have processed the scene more thoroughly than needed than to have overlooked something seemingly insignificant that later turns out to be a critical item of evidence in the investigation.
Term
packing blood soaked items in plastic should be avoided unless under what circumstances?
Definition
individual items may be placed in clean plastic bags and immediately transported to the lab for processing under extreme circumstances.
Term
What was one important lesson derived from the O.J. Simpson trial?
Definition
the focus of forensic science has shifted from the laboratory to the crime scene.
Term
What should the crime scene investigator do before any actual work begins?
Definition
Should stand back at an appropriate vantage point and formulate a systematic plan. Additionally, they should consider the following:

1. How the search should be conducted
2. What needs to be photographed
3. Where the possible locations of physical evidence may be
Term
How does the crime scene investigation begin?
Definition
documentation of the scene by the following:

1. photography
2. sketches
3. notes
Term
What should be done if an item of evidence must be moved prematurely
Definition
mark the location
Term
What are several considerations that should be made if examining an outdoor crime scene at night?
Definition
1. the scene should be kept in tact as long as possible
2. use artificial lighting
3. attempt to postpone the examination until daylight hours, or at a minimum maintain the scene to be examined a second time under normal light conditions if possible.
Term
When possible how many crime scene investigators should be utilized?
Definition
2
Term
What is a quick means to make a crime scene sketch?
Definition
upload a photo into photograph, convert it to a sketch, and print it out
Term
What are 3 essential conditions for success at a crime scene?
Definition
organization, thoroughness, and caution
Term
What is a means to conduct an indoor homicide scene?
Definition
the central crime scene can be searched beginning with the criminal's suspected point of entry and point of exit. followed by the area adjacent to the body, and finishing with the rest of the room.
Term
One is one search that can precede the crime scene search?
Definition
a preliminary inspection of the body suggest the mode of death.
Term
the trash collection point should be located where?
Definition
as far away as practical from the central crime scene.
Term
Who is equipped to collect and preserve physical evidence at a scene?
Definition
CSI officers and evidence technicians, which are police or civilian personnel specially trained to process a crime scene.
Term
What specialties may assist in producing accurate architectural editions of crime scenes?
Definition
Forensic surveyors, forensic artist, etc.
Term
What may be needed to illustrate an outdoor crime scene?
Definition
arial photographs
Term
If evidence in relation to biology and chemistry are required, who should be employed?
Definition
criminalist or forensic scientist have special training in education in the fields, that may be applied to the recognition, identification, collection, and preservation of physical evidence.
Term
What are the two main purposes of the ME/coroner system?
Definition
to determine the cause and manner of death and to identify the deceased.
Term
What other determinations might the ME make?
Definition
approximate time of death and to take custody of the remains.
Term
What is the role of the Forensic Nurse?
Definition
these professionals have training in nursing and evidence collection techniques, and other criminal justice related skills. many forensic nurses are seen in an ER type setting and may be responsible to collect sexual assault evidence as part of their duties.
Term
Who may be employed in a mass disaster scenario to identify remains based off of dental records?
Definition
forensic dentist or odontologist.
Term
When may a forensic toxicologist become involved in an investigation?
Definition
1. in product tampering cases and to examine certain bodily fluids collected at autopsy for the presence of unknown poisons or other contaminants.
Term
What does the Society of Forensic Toxicology define as the three distinct elements fo forensic toxicology?
Definition
1. postmortem forensic toxicology: assist in evaluating substances and evaluating their role as a determination for the C/M of death
2. human performance forensic toxicology:
3. forensic urine drug testing
Term
What are several functions of a firearms examiner?
Definition
1. recover spent bullets
2. asses the trajectory of fired weapons
3. determine if a bullet came from a particular firearm
4. may be able to determine if a shooting was an accident or intentional
Term
What does processing. crime scene require
Definition
a plan of action
Term
What are several general points regarding notes and note taking?
Definition
1. should be made as events unfold and in chronological order
2. detail step by step actions
3. should be complete and thorough
4. clearly and legibly written
5. negative or unexpected conditions
6. be as specific as possible
7. should be kept in the case file and retained as long as agency guidelines dictate.
8. notes are useful in adjudication as a memory refresher for the officer sometimes years later
Term
Protecting the CS is an ______ _______.
Definition
On-going concern
Term
What is a simple means to prevent unwanted superiors within your scene?
Definition
initiate a crime scene log of who enters and who exits the scene.
Term
What are several pieces of information you notes should include?
Definition
1. d/t the crime was first reported
2. type of crime
3. location of the CS and description of the area
4. name of the person who request CSI assistance
5. name of all personnel at the scene
6. name of those who processed the scene
7. weather and lighting conditions
8. description of primary scene
9. location of evidence
10. description of the surrounding area
11. description of the interior and exterior
12. d/t crime scene was concluded.
Term
What does processing of the CS include?
Definition
1. surveying the cs
2. photographing and sketching
3. mapping and measuring the CS
4. recording and documenting the location of the physical evidence
5. searching for FP, DNA, and other physical evidence.
Term
as a general rule what evidence should be collected first?
Definition
the most fleeting, fragile evidence
Term
What are several types of CS searches?
Definition
strip or lane search
grind search
spiral search
quadrant search
Term
What is one location of the CS typically overlooked?
Definition
above their heads on ceilings, up in trees, etc
Term
Before walking through the CS, what should be considered
Definition
there presence of prints located on the floor in such things as dust or dirt
Term
What is a simple technique to look for prints on a floor?
Definition
use a flashlight shines at a low or oblique angle on the floor
Term
If prints are present how should they first be photographed?
Definition
on a trip using oblique lighting
Term
in regards to evidence collection fingerprints and DNA should be searched for and collected when?
Definition
after trace evidence is collected
Term
What is recommended when taking photographs, to provide context of the what the photograph depicts>
Definition
photograph log
Term
What are several pieces of information the photograph log may include?
Definition
case number
D/T
photographers name
type of camera
lens
listing of each photograph
Term
what is important to remember regarding close-up photography?
Definition
the ruler and the parallel film plane ensure the ability later to produce a good quality engagement or a 1:1 photograph of the evidence
Term
What is the overall purpose of the photograph?
Definition
to accurately represent the crime scene as seen by the witnesses or the investigator
Term
What is a key determination on if a photograph will be admissible in court>
Definition
the investigator must be able to testify that it accurately depicts the area show. to be accurate, it must represent the subject matter properly in terms of color scale and form.
Term
What are several pieces of case-identifying information that should be included in a CS sketch?
Definition
case number
suspect, victim, and investigator names
person drawing the diagram
date and time the sketch was made
scale
legend or key
Term
What are several types of CS sketches?
Definition
overview, floor plan, or bird's eye view
elevation drawing
cross projection or exploded
perspective drawing
Term
What type of evidence should be collected first?
Definition
The most fragile such as fingerprints, DNA, and trace evidence
Term
According to the text, what is one of the most important purposes of physical evidence?
Definition
establish the identity of the suspect or victim
Term
Prints are considered ________.
Definition
conclusive evidence
Term
What are 3 possible fingers a FP examiner may render?
Definition
the subject made the print
the subject could not have made the print
the print has insufficient detail to be evaluated
Term
What does AFIS stand for?
Definition
Automated Fingerprint Identification System
Term
How are prints formed?
Definition
by friction ridges, which deposit grease and perspiration on the object touched, and may be produced when criminals take hold of an object or support themselves with their hands.
Term
How may prints be formed?
Definition
when fingers are contaminated with foreign material, such as dirt, blood, or grease, or when the fingers are pressed against a plastic material and produce a negative impression of the pattern of the friction ridge.
Term
In reference to a burglary where is one location that should be looked at for LP?
Definition
the perpetrator's point of entry or in those locations where a suspect may have eaten or drank. Additionally, light switches, circuit breakers and fuses, should be examined
Term
What are three main groups of FPs and briefly describe them.
Definition
plastic prints: occurs when the finger touches or presses against a plastic material and creates a negative impression
prints from fingers contaminated with foreign matter
LPs: result from small amounts of grease, sweat and dirt deposited on a surface
Term
What are several chemicals that may be used to enhance LPs?
Definition
amido black:
coomassie blue
dfo
fluorescence examination
gentian violet or crystal violet
iodineninhydrin
small particle reagent
Term
What is an alternate to taking inked prints?
Definition
Livescan, which is a technology that produces high-quality print cards without the need for ink
Term
What is a useful technique to lift prints from curved surfaces?
Definition
elastic or rubber materials
Term
When a print proves to be difficult to lift, what should be done prior to attempting any lifts?
Definition
it should be photographed using oblique or alternate lighting to bring out as much detail as possible.
Term
What are several techniques to lift prints from human skin?
Definition
kromekote lift technique and then fingerprint powder
Term
prints on skin typically last how long?
Definition
1.5 hours on living victims and deceased victims they should be examined as soon as possible
Term
What are two handwriting characteristics?
Definition
style: which are the general type to which cursive. belongs

personal:are changes made in the general style characteristics both internationally and unconsciously
Term
what two questions can handwriting examinations answer?
Definition
was a signature or document a forgery and

were two writings made by the same person
Term
What are two general types of handwriting exemplars
Definition
informal: or non request writing

formal: request writings
Term
what information may be determined from an examination of remains?
Definition
physical characteristics and identification
Term
what causes remains to become mummified?
Definition
when it lies in a dry place exposed to sun and air; the tissues do not putrefy but gradually dry up
Term
what is meant by a body becoming petrified?
Definition
the external parts are as if they are calcified due to formation of adipocere (grave wax) and the body resembles a marble statue. this typically takes place in a very damp environment
Term
what are issues regarding fingerprints of decomposed remains?
Definition
drying up and becoming hard, or the tissues becoming loose and filled with liquid and the epidermis becomes fragile and puckered (dishpan hands)
Term
When reading a print patter directly from a hand what must be remembered?
Definition
the print is seen reversed, as in a mirror
Term
what is one method for softening dried fingers?
Definition
let them soak in a solution of diluted liquid fabric softener for 1 or 2 days.
Term
FP changes after death can be divided into what 3 stages?
Definition
epidermis of the fingertips becomes loose and coarsely ridged
epidermis is loose everywhere and can be removed
epidermis is completely missing
Term
what are several skeletal characteristics that can be used to determine gender?
Definition
pelvis, cranium, head of joint of upper arm, Brest bone, skeleton, teeth, organs
Term
what is one portion of the body that is significant in the determination of age?
Definition
the teeth
Term
The group of primary responders for a major disaster are called what?
Definition
Disaster Mortuary Operational Response Team (DMORT)
Term
What is one of the most important factors of physical evidence?
Definition
establishing identity
Term
Trace evidence is a generic term for ______.
Definition
small, often microscopic material
Term
The concept that it is not possible to come in contact with an environment without changing it in some small way or taking something away is known as what?
Definition
Locard's exchange principle
Term
What should be avoided when packaging clothing?
Definition
plastic bags as this may lead to the development of mold or mildew
Term
What items should also be carefully examined during an examination of remains?
Definition
the clothing of the victim
Term
prior to undressing the victim what should be done?
Definition
the body should be carefully examined for trace evidence
Term
how should small items of evidence be packaged?
Definition
they should be double wrapped. the evidence should first be placed into an appropriate container and then secured and then placed into a larger container.
Term
______ samples are required in all cases?
Definition
control or known
Term
what should never be done with known and questioned samples?
Definition
they should never be packaged together
Term
when collecting paint samples from a possible hit and run how many samples should be collected?
Definition
a total of four should be collected and separately packaged. from vehicle a collect a sample from the point of impact that contains a transfer from vehicle b. also collected a standard from a no damage location. collect two of the same from vehicle b
Term
where should removal of fibers from objects be conducted?
Definition
at the laboratory
Term
what are two types of fractures in broken glass?
Definition
radial: cracks that start at the center or point from which the object struck the glass and run radially outward.

concentric: form concentric circular cracks in the glass around the point of impact
Term
what is a clue when examining glass in regard to which side of the glass the force was applied?
Definition
the edge of a concentric fracture, the side of the glass forming the right angle with the rib markings is the side from which the force came.
Term
what are several answers an examination of hair may be able to provide?
Definition
species, location of growth on the body, hair treatment, hair disease, and whether hairs fell out naturally or were forcibly pulled out.
Term
where and how many hairs should be collected for examination?
Definition
hairs should be collected from the entire body, and specifically hair should be collected from several locations of the head with about 25 hairs from each spot.
Term
what is the first question a criminalist will attempt to answer regarding hair?
Definition
is the hair animal or synthetic in origin
Term
What should the CSI consider whenever working around blood?
Definition
Using the appropriate PPE such as Tyvek, gloves, mask, etc.
Term
What is a major concern in regards to handling DNA or biological evidence?
Definition
contamination
Term
what word describes the act of making impure or unsuitable by contact or mixture with something unclean or foreign?
Definition
contamination
Term
crime scene equipment should be cleaned after use using what?
Definition
10% bleach solution followed by 70% ethanol
Term
Any individual who enters a CS, should submit what for elimination purposes.
Definition
DNA sample
Term
What are the three basic classifications of bloodstains?
Definition
passive, spatter, and altered.
Term
what are two types of bloodstains?
Definition
impact spatter and transfer stains
Term
what is blood spatter?
what is a transfer stain?
Definition
blood that travels through the air from an impact mechanism
stains resulting from contact with a bloody surface
Term
what formula can reveal the angle of impact for a blood stain?
Definition
Sin-1(W/L)
Term
what may help determine the direction of travel of a blood stain?
Definition
the tails end of the individual stains
Term
what are several general terms established by the Scientific Working Group on Bloodstain Pattern Analysis, used to describe various blood marks at a scene?
Definition
bloodstain, swim, wipe, spatter, drip stain, exported blood, parent stain, satellite stain
Term
What is a void?
Definition
term used to describe an area within a generally continuous bloodstain patter that lacks bloodstains.
Term
what are several chemicals that may be used as presumptive blood test?
Definition
leucomalachite green, phenolphthalein, orthotolidine, etc
Term
what are presumptive test and what do they rely on?
Definition
color spot test that depend on properties fo hemoglobin
Term
according to the text, what are the two most sensitive presumptive blood test?
Definition
orthotolidine and tetramethylbenzidine
Term
what else may presumptive blood test return a positive result for?
Definition
animal blood and certain types of plant materials
Term
according to the text what is a good overall choice for presumptive blood test?
Definition
phenolphthalein (Kastle-Mayer test)
Term
according to this text what is another presumptive test that can be used to search for large areas of latent blood?
Definition
luminol (remember during blood spatter week, this was noted not to be considered a presumptive test)
Term
luminal reacts with blood and gives off light by a process known as ________.
Definition
chemiluminescence
Term
one is one non-chemical method to search for latent blood?
Definition
oblique lighting or IR lighting
Term
the search for blood on clothes must be carried out ______ and _______.
Definition
carefully and systematically
Term
what are ways to preserve the bloodstain itself?
Definition
through notes documenting their form, color, size, position, direction of the splash. As well as to extensively photograph the bloodstains
Term
how should bloodstains be packaged?
Definition
air dry the sample in a paper bag and then seal and store at room temperature.
Term
what is the easiest method to collect wet blood?
Definition
place a cotton swab into the still liquid pool of blood.
Term
what is a easy means to collect dried blood?
Definition
use a sterile cotton swab moistened with sterile distilled water
Term
generally how much of a bloodstained object should be submitted?
Definition
the entire bloodstained object when possible.
Term
damp bloodstained clothing should always be allowed to ______.
Definition
air dry
Term
if an item containing blood is too large to collect, besides a cotton swab what else may be done?
Definition
cut out the relevant portion of the object
Term
how can semen stains be searched for?
Definition
using an ALS, once located an acid phosphatase presumptive test can be utilized and then confirmed with an prostate specific antigen test utilized
Term
how is DNA depicted pictorially?
Definition
twisted ladder or double helix
Term
what are the four chemical subunits or steps in the DNA ladders?
Definition
guanin (G), adenin (A), thymine (T), and cytosine (C). these base pairs always line up in the following format A with T and G with C
Term
DNA is not present where in blood?
Definition
red blood cells
Term
where is DNA located within blood?
Definition
the white blood cells
Term
what are other portions of the body DNA is located?
Definition
seminal fluid, tissues, bone marrow, hair roots, etc.
Term
what is polymerase chain reaction (PCR)
Definition
a technology that copies short segments of DAN millions of times in a process that resembles the way in which DAN duplicates itself naturally within the body
Term
explain the PCR testing process
Definition
after separating the DNA double helix, a PCR reaction mixture is added. this procedure is performed in an instrument called a thermocycler and is typically repeated for 28 cycles, approximatlely doubling the amount of DAN after each cycle
Term
what is used to recover and detect small amounts of DNA?
Definition
high-sensitivity DNA
Term
what are several candidates for high-sensitivity testing?
Definition
car swabs, handles of weapons/tools, keys, pens, air bags, etc.
Term
what separates mtDNA testing from other test?
Definition
much smaller molecule
only inherited maternally
mtDNA is present within cells in multiple copies
Term
mtDNA has several applications, but what is one major example of when it would be used?
Definition
as an investigative tool in missing persons identifications
Term
mtDNA is another valid choice for what reasons?
Definition
DNA may degrade due to environmental insults, or aging. The high copy number of mtDNA means a higher likelihood of survival of intact sequences that can be applied to PCR based technology
Term
Y-STRs are found in which sex?
Definition
male because they possess an X and a Y chromosome
Term
what does CODIS stand for and what is it?
Definition
Combined DNA Index System, and it is an FBI sponsored initiative where offender DNA samples are stored and used to generate investigative leads in future investigations
Term
what are 4 other components fo CODIS?
Definition
arrestess, missing persons, biological relatives of missing persons, unidentified human remains
Term
what is the Scientific Working Group on DNA Analysis Methods?
Definition
a group of forensic DNA analysis from various locations throughout the US, that have developed guidelines on QA/QC pertaining to DNA testing standards implemented in labs.
Term
In many instances, very small and sometimes microscopically unique markings are left that can be traced directly to the object or instrument in question. Such marks caused by a tool are of what two general types:
Definition
compression and marks
Term
what are compression marks?
Definition
marks left when an instrument is in some way pushed or forced into a material capable of picking up an impression of the tool
Term
what are examples of compression marks?
Definition
shoe impressions, tire impressions, bite mark impressions, etc.
Term
what are scraping or striated marks?
Definition
marks produced by a combination of pressure and sliding contact by the tool and result in microscopic striations imparted to the surface onto which the tool worked
Term
what are examples of scraping marks?
Definition
those found on bullets, left by a cutting cool, from an ax used to cut wood, screwdriver blade dragged over a surface
Term
what is required for compression or scraping marks to be observed?
Definition
the tool must be made of a harder material than the object on which it is used.
Term
what causes the random nature of the microscopic imperfection found on a tool?
Definition
manufacture and usage
Term
how is impression-type evidence studied?
Definition
comparative examination
Term
why would you preserve individual footprints?
Definition
if they contain details of value for identification.
Term
what are the most valuable details of footprints?
Definition
signs of wear, characteristic fittings or marks of fittings tan have come off, injuries, marks of nails and pegs, etc.
Term
although the _____ and ______ of a shoe or a pattern in the heel or sole is oaf lesser evidential value, it should be persevered none the less.
Definition
size and shape
Term
what causes a footwear impression?
Definition
when the foot treads in some moldable material such as each, sand, clay, snow, etc.
Term
what causes footprints to form on a hard base?
Definition
when the foot or the sold and heel of a shoe are contaminated with some foreign matter such as road dirt, dust, flour, blood, etc.
Term
what may gait pattern indicate?
Definition
the subject was walking or running, had sustained an injury or walked with a limp, was possibly intoxicated, etc.
Term
where are footwear impressions generally found?
Definition
outdoors
Term
what is the first precautionary measure in regards to footprints?
Definition
to protect the impression from alteration or destruction, preferably by covering it with a box or cordoning off the area.
Term
what are techniques to prevent an impression from being destroyed due to running water?
Definition
if in thawing snow cover the box that is covering the impression with snow.

if running water, surround the impression with a wall of earth, sand, or snow, or dig a hold close to the impression that will allow water to drain.
Term
what is a simple procedure to locate indoor prints?
Definition
turn off the lights and use a high intensity flashlight at a low angle to search surfaces
Term
what is a means to preserve footwear evidence?
Definition
photography and casting, if it is a dust print photograph and lift
Term
what type of photography in regards to evidence is most commonly messed up
Definition
photographing shoe and tire impressions
Term
what are some of the reasons foot/tire impressions may not be properly photographed?
Definition
not using a tripod, not shooting perpendicular to the impression, failing to use a scale, and not using oblique lighting
Term
what are some general rules for taking photographs of foot/tire impressions?
Definition
vertically above the impression on a tripod with scale on the same plane as the impression. file plane parallel, use two scales at right angles to each other
Term
before photographing ______ should be removed if it can be determined it has fallen in after the impression was made?
Definition
debris, do this using a set of tweezers
Term
materials _______ into the impression should not be removed.
Definition
tramples, such as leaves or grass as if they were pushed into the impression while it was being made there will be no detail under them
Term
what are some methods to get better photographs of impressions in snow?
Definition
dust the impression with aluminum powder
Term
because foot impressions are _________, the photograph should be made under illumination that will bring out detail.
Definition
3D
Term
how are foot/tire impression usually cast?
Definition
dental stones, with paraffin, sulfur, and silicone rubber being used less frequently
Term
what is the proper ratio for dental stone?
Definition
2 pounds of dental stone to about 12 ounces of water. this mixture in conjunction with a retaining wall should allow for the impression to be cast appx 2 inches thick
Term
what problems arise with casting snow impressions with dental stone?
Definition
the mixture beings to heat up. to circumvent this, a small amount of snow or ice should be added to the mixture
Term
how should dental stone be poured?
Definition
it should be gently poured onto an area adjacent to the impression and allowed to flow onto the impression.
Term
before the casting hardens how should it be marked?
Definition
date, investigators name, case number, location of the impression
Term
______ and ______ clinging to the cast should not be disturbed and the cast should be allowed to air dry for ______ hours.
Definition
clumps of solid and rocks, and 48
Term
when casting an impression in snow how is the impression prepared?
Definition
by first spraying a thin layer of snow print was into the impression
Term
what is another method for casting snow impressions?
Definition
surfer casting
Term
regardless of the medium how are footprints always preserved?
Definition
photography
Term
after footprints in dust are photographed what methods should be applied for further collection?
Definition
recover the object which the print is on
lifting by special lifter
lifting by photographic paper
lifting by static electricity
Term
how are comparison footprints taken?
Definition
the soles are coated with water based ink. the inked shoes are then carefully stepped onto a sheet of tracing paper or acetate shoe.
Term
to get a true picture of the formation of the sole of the foot in different position what samples are obtained?
Definition
normal standing,
standing position with pressure agains the outside of the foot
standing with pressure against the inside of the foot
walking
Term
what is another method obtain known footwear exemplars?
Definition
talcum powder and black carbon paper
Term
what is important to remember regarding prints or impressions of shoe covered feet?
Definition
they are seldom the same size as the shoes; even when they re made, slipping and the movement of walking can damage prints.
Term
a foot impression in ______ _____ can become appreciably smaller when the earth dries; in ______, the length can decrease by up to ______ of an inch
Definition
wet earth, clay, and 3/4
Term
in regards to foot impressions, what is more important that size?
Definition
to establish identity, the circumference characteristics should be checked.
Term
how should bite marks be preserved?
Definition
photography and casting
Term
what is a method to preserve bite marks in fruit?
Definition
they may be able to be preserved in .5% formalin solution, which prevents changes resulting from drying/decaying of the fruit
Term
what is a good practice to confirm identification from a bite mark?
Definition
swab the bite mark for DNA
Term
what is typically required to obtained the best evidentiary photographs of bite marks?
Definition
oblique lighting
Term
what are two general types of tool marks?
Definition
those in which only the general form and size of the tool are apparent and those in which injuries irregularities, and the peculiar characteristics are reproduced in the form of striations or indentations.
Term
what is the most valuable tool mark evidence?
Definition
tool marks that show striations, indentations, or similar details resulting from damage or other irregularities in the tool
Term
whenever possible, tool marks should be kept what?
Definition
in their original condition
Term
what should only be used as a last resort for taking impressions of tool marks?
Definition
casting or other materials
Term
where at crime scenes should be examined carefully for tool marks?
Definition
doors, windows, locked drawers, etc.
Term
ballistics generally refers to what?
Definition
the trajectory taken by a projectile and assumes an understanding of physics.
Term
firearms identification is the study of what?
Definition
firearms and includes the operation of firearms, cartridges, GSR analysis, bullet cartridge cases comparisons, powder pattern determinations, etc.
Term
firearms are broadly classified into what two groups?
Definition
rifles and shotguns and handguns
Term
what are two other categories may be classified in?
Definition
the type of bore they have being either a smooth or rifled barrel.
Term
what is rifling?
Definition
is the spiral grooves cut into the barrel that impart a rotation motion to the bullet as it leaves the barrel to provide stability during flight
Term
firearms may be _____ shot, _______, _______, or ________.
Definition
single shot, revolver, automatic, semi-automatic
Term
what are two major ways shotguns differ from other firearms?
Definition
shotgun barrels are usually not rifled and fire a different type of ammunition consisting of many lead pellets, rifled slugs, sabots, or shot.
Term
one basic function of firearms examination is what?
Definition
determine that two rounds were fired from the same weapon.
Term
what is other information a firearms examination may be able to provide?
Definition
a casing may indicate the type of firearm, i.e. automatic, semi, etc.
may be able to tell where a shooter was inside of a scene
bullet fragments can be examined, the number and direction of twist, etc
Term
according to some studies, what is the length of time GSR may remain on an individuals hands?
Definition
for up to 6 hours
Term
how is GSR evidence collected?
Definition
cotton tip applicators and dilute nitric acid solution for AA and ICP analysis or with aluminum stubs with double sided cellphone tape for SEM
Term
what are lab test to confirm the presence of GSR?
Definition
atomic absorption spectrophotometry, scanning electron microscopy/energy dispersive X-ray analysis, inductively coupled plasma (ICP) spectroscopy.
Term
what are common chemical make ups of most ammunition?
Definition
lead barium, and antimony
Term
negative GSR results do not confirm _______ and positive GSR results to not confirm ________.
Definition
do not conclusively mean a subject didn't fire a gun and positive do not prove someone fired a gun
Term
due to the ambiguity in conclusions of GSR test, what is the stance of many labs regarding its testing?
Definition
they have opted to discontinue this service
Term
what should happen if a weapon is found at a scene?
Definition
it should not be moved until its location is noted, through measurements, sketches and photographs. Only in extreme circumstances should the weapon be moved before
Term
what is important to note if a deceased individual is holding the gun and why?
Definition
the exact grip and position of the weapon in the hand, as it could be a staged scene
Term
what may be just as important as information from the weapon?
Definition
the position of cartridges, cartridge cases, and bullets.
Term
what evidence may a weapon used in a murder, suicide, or assault contain?
Definition
blood, hair, fragments of textiles, cloth fibers, etc
Term
what is common in close proximity gunshots?
Definition
blood, grease, etc, may be forced into the barrel of the gun and is referred to as backspatter
Term
when should a gun be unloaded and rendered safe?
Definition
after it has been processed for prints and swabbed for DNA
Term
what are the most valuable markings on a cartridge casing?
Definition
those made by the firing pin on the primer and by the breech face on the primer and bas of the case, but the extractor and ejector, and the edge of the breech markings may also be important
Term
marks made by the extractor, ejector, and edge of the breech, may be able to reveal what?
Definition
which gun fired it
Term
Arson is defined as what?
Definition
the willful and malicious burning of another's property or the burning of one's own property for some illegal purpose such as defrauding an insurer.
Term
______ and ______ crime scenes are unique in the amount of destruction and devastation present.
Definition
arson and explosion
Term
what questions should the arson investigator focus on?
Definition
where did the fire originate
how was the fire started
was the cause of the fire an accident or was it intentionally set
Term
what is the most commonly sought physical evidence n arson investigations?
Definition
ignitable fluids
Term
ignitable fluids are highly ______ and ______ easily.
Definition
volatile and evaporate
Term
how should volatile substances be packaged?
Definition
clean metal paint cans, with an alternate being glass jars with metal screw caps
Term
what are several examples of accelerants?
Definition
gasoline, kerosene, charcoal lighter fluid, paint thinner, turpentine
Term
an arson investigation should also search for igniting materials, such as what?
Definition
match books, candles, black powder, smokeless powder, sodium and water, electrical devices, should all be noted and collected.
Term
what are two broad classifications of explosives?
Definition
low explosives: these explosives burn rather than explode. these are caused by force exerted by the rapid expansion of gases formed by burning.
high explosives: consist of primary and secondary explosives. in general, these are detonated by shock and having much higher detonation velocities.
Term
what is the most common type of low explosives?
Definition
black powder which is a mixture of potassium or sodium nitrate, sulfur, and charcoal. black powder is sensitive to heat, impact, friction, and sparks.

smokeless powder is another low explosive. smokeless powder is marketed as either a single base consisting of nitrocellulose, or double base, which is composed of nitrocellulose and nitroglycerine.
Term
what causes primary explosives to detonate?
Definition
when they are subjected to heat and shock
Term
what are two types of blasting caps?
Definition
electric and nonelectric
Term
det cord is a cord like explosive that contained a central core of what?
Definition
RDT or PETN covered with cotton or other textile, followed by a waterproof material or plastic covering
Term
_____ and _____ explosives are used to detonate very insensitive high explosives.
Definition
boosters or primer
Term
what does the booster consist of?
Definition
a secondary explosive such as RDX, PETN, tetryl, or pentolite and is detonated by a blasting cap
Term
what are the four basic types of dynamite used today?
Definition
straight dynamite, ammonia dynamite, gelatin dynamite, and ammonia-gelatin dynamite
Term
ammonium nitrate in a less pure form is called what?
Definition
fertilizer, in its our form, it is a white crystalline material, as an explosive it is relatively insensitive and requires a booster to detonate.
Term
what is ANFO considered?
Definition
a blasting agent and consist of 94% ammonium nitrate and 6% fuel oil
Term
what are sheet explosives?
Definition
flexible rubber like sheets approximately 1/4" thick that can be cut with a knife.
Term
what are the high explosives used?
Definition
RDX and PETN
Term
c4 contains what % RDX?
Definition
91%
Term
what are flashbulbs?
Definition
may be used to ignite heat sensitive explosives such as black powder.
Term
what is ammonium nitrate fertilizer?
Definition
ammonium nitrate mixed with fuel oil and an appropriate booster. it makes an extremely effective homemade explosive device
Term
what are several questions physical evidence may answer in bombing cases?
Definition
what materials were used to make the explosive device
what was the level of skill or expertise of the suspect
what was the target of the bomb
was the explosion accidental or was there criminal intent
where was the bomb made/placed
where did the suspect obtain the material
who was the victim or intended victim
who made the bomb and who placed it
how was it detonated.
Term
in a bombing investigation how does the crime scene investigators duties change?
Definition
they do not; however, the investigator will have an additional consideration: safety will be the major concern.
Term
according to the text what is the first drug referenced that find their way into police investigations?
Definition
psychoactive drugs, which affect the user's psychological process or change their mood.
Term
what are the 8 major categories of drugs discussed in the text?
Definition
CNS depressants, CNS stimulants, hallucinogens, cannabis, designer drugs, nonprescription drugs, inhalants, and steroids
Term
_______ are an important class of CNS depressants.
Definition
narcotics which are used medically for their analgesic properties and have a high potential for abuse.
Term
what are two categories of narcotics?
Definition
spiate alkaloids and synthetics or semisynthetic
Term
what is the most frequently encountered opiates?
Definition
raw opium, morphine, and iodine
Term
what are analgesic substances?
Definition
painkillers
Term
what are opiate alkaloids derived from?
Definition
opium poppy
Term
what are sedative hypnotics?
Definition
these are CNS depressants and are generally prescribed for treatment of insomnia and tension and have a high potential for abuse and addiction.
Term
what are other types of drugs included in the sedative hypnotic class?
Definition
barbituric acid derivatives such as secobarbital, amobarbital, phenobarbital, and non barbiturates such a doriden, quaalude, and chloral hydrate
Term
what is a third category of CNS depressants?
Definition
tranquilizers and energizers.
Term
what are the major and minor groups of tranquilizers?
Definition
major: chlorpromazine, prochlorperazine, trifluoperazine, etc. these are prescribed for neurosis, psycosis, and other psychological disorders and are considered addictive

minor: may produce psychological dependence with prolonged use, and include substances such as midtown, librium, valium, etc
Term
what is the most widely used CNS depressant today?
Definition
ethyl alcohol
Term
what is a major CNS stimulant?
Definition
cocaine
Term
what is the third class of stimulants?
Definition
amphetamines and include drugs such as benzedrine, dexedrine, desoxyn, etc. this group also includes non amphetamine stimulants such as Ritalin and preludin
Term
what is one group of drugs that currently has no accepted medical use?
Definition
hallucinogens
Term
what are several drugs in the hallucinogen group?
Definition
mescaline, psilocybin, LSD, DMT, etc
Term
what is the legal definition of pot?
Definition
derivatives from the plant Cannabis sativa, and is most often consumed by smoking crushed tops and leaves or resinous material which contains THC
Term
what category is pot classified in?
Definition
pharmacologically, none
Term
in regards to contraband and drugs where might an investigator focus their search?
Definition
in hidden locations, on a person, in a dwelling, or in a vehicle
Term
what is toxicology?
Definition
the study of poisons. in regards to drugs, it expands the definition to include the detection of drugs and alcohol in blood and urine samples
Term
what are the 5 drug schedules in the US
Definition
Schedule I: high potential for abuse and no accepted medical use
Schedule II: high potential for abuse currently has an accepted medical use with severe restrictions
Schedule III: potential for abuse less than I or II, has an accepted medical use
Schedule IV: low potential for abuse relative to Schedule III, and has an accepted medical use
Schedule V: low potential for abuse relative to Schedule IV, and has an accepted medical use
Term
list several examples of each drug schedule.
Definition
Schedule I: heroin, LSD, pot
II: morphine, PCP, cocaine
III: anabolic steroids, codeine, hydrocodone with asprin
IV: Darvon, talwin, equanil
V: over the counter cough medicine with codeine
Term
how should a SA victim be treated?
Definition
nonjudgmental and with sensitivity
Term
what are several reasons why seminal fluid that would be expected to be found is not?
Definition
time period between the assault and the exam
suspect wore a condom
suspect penetrated but did not ejaculate
the doctor or nurse didn't take adequate samples
seminal fluid may be present from a consensual encounter
seminal fluid without spermatozoa may be present due to the subject undergoing a vasectomy
Term
what are 3 major purposes of physical evidence in SA cases?
Definition
to establish sex occurred
to establish nonconsensual intercourse occurred
establish the identity of the subject
Term
what are two related problem areas in regards to child molestation and incest?
Definition
difficulty in interviewing the victim
possible problems regarding the child's competency to testify
Term
what is one of the most common crimes encountered by LE?
Definition
burglary
Term
in regards to a burglary investigation what is one of the most important locations to search for evidence?
Definition
the point of entry
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