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CRIM 208 - Forensic Science FINAL (Exam 3)
Dr. Katherine Roberts - CSULA
59
Criminal Justice
Undergraduate 2
03/13/2014

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Term
Different Presumptive Tests for Blood
Definition
Phenolphthalein, Leucomalachite Green. Answers the question: Is this substance blood?
Term
Phenolphthalein
Definition
Clear chemical. When mixed with blood and Hydrogen Peroxide, turns pink. Used as a presumptive screening test.
Term
Leucomalachite Green (LMG)
Definition
Clear chemical. When mixed with blood turns green.
Term
Luminol
Definition
Used when blood can not be seen. When combined with an oxidant and sprayed over area with blood, then it glows blue. Chemiluminescent. Problem of destroying blood after spraying.
Term
Tests to screen for the presence of blood
Definition
Luminol. It answers the question: "Is there any blood here?"
Term
What can you say if you obtain a positive screening for blood?
Definition
I might have blood, but the sample could be some other contaminants like bleach. I can not answer if this is human blood or any particular person's blood.
Term
Tests to confirm that a stain is blood
Definition
Teichmann Test and Takayama Test
Term
Teichmann Test/Takayama Test
Definition
Small amount of blood is added to a microscope slide and mixed with either chemical solution. Slide is heated to form crystals and are viewed under a microscope for a distinct crystal pattern.
Term
Test to confirm a blood stain is human blood.
Definition
Ouchterlony Double Diffusion Test
Term
Ouchterlony Double Diffusion Test
Definition
A gel plate is created with holes to place different serums or anti-serums. The anti-human is placed in the center, the known human blood and crime scene sample is placed in their own other holes. Other holes have different anti-serums for different animals. Precipitate lines are formed when the serums and blood mix. Compare the known human sample to the crime scene sample.
Term
Test to confirm a blood stain belongs to an individual person
Definition
Nuclear or Mitochondrial DNA
Term
Nuclear DNA
Definition
Most discrimination, Nucleus contains the DNA contains the genetic makeup of a person
Term
Mitochondrial DNA
Definition
Maternally transferred DNA, can not trace a particular person, can only reduce down to maternal offspring of the person's mother.
Term
Presumptive Tests for Semen
Definition
Color tests for SAP (Seminal Acid Phosphotase)
Term
Seminal Acid Phosphotase (SAP)
Definition
Found in many different tissue and fluids, but very concentrated in semen. Synthesized in the prostate. Present in males from puberty to 40 years of age, amount declines after 40. Detection still present after vasectomy, without sperm.
Term
What can you say if you obtain a positive screening for semen?
Definition
Able to narrow down that the stain is either semen or from human tissue or fluid.
Term
Tests to confirm that a stain is semen
Definition
Microscopic identification of spermatozoa and P30 (Prostate-Specific Protein)
Term
Christmas Tree Stain & H and E Stain
Definition
Used to confirm sperm. Sperm cells are stained before observing microscopically. Stains the sperm heads red and the tails green. Sperm is viewed 400X magnification. Only 1 sperm cell is needed to confirm.
Term
P30 Test
Definition
Confirm the presence of prostate specific proteins in a sample after a positive SAP test. Tester confirms with a positive result on the control band and the test band. Negative if only control band. Inconclusive if nothing happens, the tester is broken.
Term
Tests to screen for the presence of saliva
Definition
Starch-Iodine Test
Term
Starch-Iodine Test
Definition
For detecting Amylase, an enzyme in Saliva used to break down starch. When starch and iodine is mixed it turns blue, if Amylase is added the blue color will begin to vanish. Amylase is also in blood, semen, and other bodily fluids, so it can not be used to confirm saliva.
Term
Buccal Cell Test
Definition
Extracted from saliva stains for DNA extraction.
Term
Advantages of mitochondrial DNA
Definition
Can be used to deduce suspect to a number of people related maternally. It is present in many forms of body cells, not just in blood or semen.
Term
Fraction of blood contains DNA
Definition
the white blood cells contain DNA and makes up 1% of blood.
Term
Epithelial Cell or Buccal Cell locations of presence
Definition
Can be found in the mouth, cheek, or vaginal tract. Found in saliva or vaginal fluid.
Term
Polymorphic proteins
Definition
Different serum proteins or enzymes have differences that can be detected by separating the proteins in a gel by electrophoresis.
Term
Forensic evidence used to support a sexual assault case
Definition
Swabs taken from the victim's skin, mouth, vagina, and rectum. Clothing like underwear that was worn during the assault.
Term
Widmark Curves
Definition
Depicts the level of blood alcohol content to the time after start of drinking. An upward motion indicates absorption of alcohol, while a downward motion indicated eliminated alcohol by the liver. Steep curves indicate fast ingestion of alcohol, low curves indicate low alcohol absorption, typically from alcohol consumption after a full stomach.
Term
Qualitative Analysis
Definition
Determine what something is.
Term
Quantitative Analysis
Definition
Determine how much of something there is.
Term
LD50 Value
Definition
Lethal dose of 50% of the population. Number determined through lab testing on rats and mice. The lower the number, the more lethal a substance is, the less you need to kill someone.
Term
Metabolites (Problems with analyzing toxicology samples)
Definition
Drugs breakdown in a body and produce a less harmful product. Makes detection very time sensitive, before all the drug breaks down.
Term
Tissue Selection (Problems with analyzing toxicology samples)
Definition
Drugs could be highly concentrated in certain areas of the body, depending on how the drug is being ingested or taken.
Term
Sensitivity (Problems with analyzing toxicology samples)
Definition
Instruments need to ba highly sensitive to find a small amount of drug in the body.
Term
Matrix Problems (Problems with analyzing toxicology samples)
Definition
Some drugs don't go to blood or urine. Samples like liver, bile, or stomach samples can only be collect post-mortem.
Term
Evidence found at a clandestine lab
Definition
Equipment or apparatus used to make drugs. Chemicals with the ingredients to make drugs together. The "in process" manufacturing stage identified and the final product.
Term
External signs of a clandestine laboratory
Definition
Odd or excessive amounts of trash in the form of pill containers, lab glassware, coffee filters, bed sheets, and misused propane cylinders. Unusual or strong odors. Discoloration in the soil or lack of vegetation.
Term
Equipment or apparatus (Clandestine Lab Evidence)
Definition
Items like buckets, lab glassware, bed sheets, or anything that could be used. Clean or with residues.
Term
Chemicals (Clandestine Lab Evidence)
Definition
High quantities of pseudoephedrine, red phosphorus, or any other ingredient used for meth production. Ingredients found together shows intent of making.
Term
Identification of "In Process" stages (Clandestine Lab Evidence)
Definition
Any stage of the drug phase that can be identified can be used as intent of producing the drug.
Term
Final Product (Clandestine Lab Evidence)
Definition
Can obviously be used to convict, but also without shows intent to make as long as the ingredients and/or equipment is found together, or is in the process of making a drug.
Term
Factors affecting absorption of alcohol
Definition
Surface area (size of the person), speed of blood flow in the individual, the amount or any presence of food, and the alcohol percentage of different types of beverages.
Term
Factors affecting the elimination of alcohol
Definition
The functionality of the liver to produce enzymes to break down alcohol, chronic consumption causes more efficient break down, and amount of food eaten.
Term
Techniques to screen for controlled substances
Definition
Color tests, Microcrystaline Tests, Thin Layer Chromatography, UV Spectroscopy
Term
Color Tests (controlled substance screening)
Definition
Certain parts of chemicals react with color reagents differently. Add color reagent to unknown substance to find a positive reaction. Three common color tests for heroin are the Froehde, Marquis, and Mecke tests.
Term
Microcrystaline Tests (controlled substance screening)
Definition
Usually performed after color tests, can be specific, but not confirmatory based on the Daubert Standard because there is no scientific reason for why these crystal formations happen. Each drug has a specific crystaline pattern.
Term
Thin Layer Chromatography (controlled substance screening)
Definition
Involves the separation of components of a mixture and comparison to known standards. Spots of known substances are put in individual columns and then the unknown substance spot on a plate. The plate is placed in a chamber with a reactant liquid from the base of the plate. The liquid rises, with certan substances rising faster or slower than others and a stopping spray stops the movement of the spots. Then the known samples and the unknown are compared.
Term
UV Spectroscopy (controlled substance screening)
Definition
Different drugs create a different pattern, creates a graphed pattern. Can be used to determine the identity of the family a drug belongs to. Can also determine the concentration of a particular type of drug.
Term
Techniques to confirm controlled substance
Definition
Gas Chromatography Mass Spectroscopy and Infrared Spectrascopy
Term
Gas Chromatography Mass Spectroscopy (Controlled Substance confirmation)
Definition
Separates compounts by their affinity to the stationary and mobile phases and then hooked up to mass spectrometers for final confirmation. Does not need to be a pure drug, can be mixtures because it will separate the drugs for you. Able to set up batchs of 150 different cases and finish over night. The more expensive option.
Term
Infrared Spectroscopy (Controlled Substance confirmation)
Definition
The use of infrared to confirm a substance, but can not determine mixtures. Must be separated before using this method.
Term
Basis for Scheduling drugs in the Controlled Substance Act
Definition
Drugs must have a potential for abuse, potential for psychological dependence, and does the drug of medicinal value.
Term
Schedule I Drugs
Definition
The drug must not have any medicinal value
Term
Cannabis Preparations
Definition
Leaf, Hash, or Oil
Term
Leaf preparation of Cannabis
Definition
Can be confirmed through microscopic examination.
Term
Hash and Oil Preparation of Cannabis
Definition
Can not be confirmed through microscopic examinations. Can only be confirmed through THC Color Test called the Duquenois-Levine Test or Gas Chromatography Mass Spectroscopy.
Term
Microscopic Examination of Marijuana
Definition
Cystolithic hairs on the surface of the marijuana leaf. Very fine hairs on the underside of leaves
Term
Duquenois-Levine Test
Definition
Color test accepted as confrimatory when used in conjunction with microscopic examination. Liquid turns purple when combined with THC. Without microscopic examination, confirmed with GC-Mass Spect.
Term
What can drug color tests tell us?
Definition
Used to deduce the probable identity of the substance, but may be other substances as well. i.e. tests of cocaine can react with other "caine" drugs like lidocaine, benzocaine, novacaine, etc.
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