forensic exam 3

the three classifications of substances by CH, bonding and formats

the inner structure of substances

protons, neutrons and electrons

the modified griess test

a nondestructive test of GPR that is sprayed onto the skin or clothing; if it turns pink it is positive

five types of gunpower

2 kinds of flakes, balls, discs, cylinders

the SEM examination

can enlarge GSR half million- a million times

GSR

Gun shot reside; made of lead, antimony and barium

GPR

gun powder reside; multiple kinds

organic materials

carbon based compounds

inorganic materials

compounds that dont contain carbon

element

the building blocks of all matter

compound

substances that are composed of two or more elements chemically combined

mixture

matter consisting of two or more pure substances that retain their individual identities and can be separated

alloy

a mix of metals in different ratios

protons

Positively charged particles

neutrons

the particles that have no charge

electrons

Negatively charged particles

atomic number

the number of protons in the atom

atomic mass

sum of protons and neutrons

atomic weight

weight average of all isotopes

contusion ring

soot or smoke around the bullet wound

abrasion ring

cone shaped, star, torn, from contact or close to contact shot

isotopes

same carbon property of an element but different atomic mass

ions

positively and negatively charged atoms

burned poweder

part of GPR, can be used for testing

unburned powder

allows for chemical testing, part of GPR, griess test can be conducted on

soot

burned powder

stippling

comes from close range; little dots on the skin

particles

small amount; typically from unburned powder

micrometer

how SEM is measured

quality analysis

confirms the presence of a molecule or element

quantity analysis

determines the compound present and its concentration

the major components of human blood and its testing steps

erythrocytes, leukocytes and thrombocytes

the principles of luminol and seratec tests

testing of body fluids through spray

the ABO typing system

broad classifications based on antigen A or antigen B

the principle of the pythagorean theorem on the blood angle calculation

cos (angle)= shorter angle/ longer angle

the principle of saliva and semen tests

presence of salivary amylase and seminal stain

erythrocytes

red blood cells

leukocytes

white blood cells; carry DNA

non human blood samples

blood samples from animals

non blood samples

spinach, horseradish, bleach, metals, etc.

presumptive tests

a preliminary test to determine if the red stain is a human blood with a possible mistake but good for plea bargain

confirmatory tests

refer to a second test by advanced techniques

luminol

can detect the iron in blood from mixes as low as 1-1 million mixtures; dark blue light is positive

seratec tests

tests on blood, saliva and semen

hemoglobin in blood

can be detected by luminol and seratec

iron element in blood

in hemoglobin and can be detected by luminol

sine

used to determine the angle of blood spatter

cosine

inverse of sin

false positive tests on blood

a positive test when it should be negative; could be caused by horseradish, spinach, bleach, and certain metals and plants

false negative tests on blood

a negative test when it should be positive

type AB blood

3% of people have; master receiver because they have both A and B antigens

type O blood

43% of people have; master donor because they have neither A or B antigens

spinach by luminol

can produce a false positive

blood by luminol

a test that detects the iron in blood, can be applied to large areas, is very sensitive and cheap

n-DNA

nuclear DNA; can be used to pin down an individual

the brief DNA history

the DNA roadmap

the flow from largest part of the genome to the smallest part

the pitchfork syndrome

believing you can get away with murder after leaving DNA on the scene

the two DNA comparison methods (the sequential order and the allele)

DNA coding- sequential order; number of repeats; allele method

the supreme court decisions on DNA examination

50 states require samples to be collected from those convicted of felonies; 28 states and the federal government currently collect DNA samples from arrestees for felonys

the coded gene

only 1 percent of genes

non-coded gene

99 percent of the genes

genome

the entirety of the human makeup; the world

chromosome

A specific part of the genome, CA

gene

a region of DNA that helps determine a characteristic; Long Beach

locus/loci

a specific spot on a chromosome occupied by and repeats vary by individuals; a neighborhood in Long Beach

alleles

number of repeats by STR in the junk area; number of same looking houses in a neighborhood

TA base pair

2 hydrogen bonds

GC base pair

3 hydrogen bonds

the letter order

a sequence of expression

the alleles methods

two numbers of the repeats at each locus from two parents for 26 numbers

PCR

polymerase chain reaction; can amplify a partial DNA by two steps

STR

short tandem repeats; locations/markers on genes; less likely to degrade

f-DNA

familial DNA

m-DNA

mitocondrial DNA that can narrow down a suspect to siblings of a mother; 1,000 per cell

Y-DNA

DNA found in the Y chromosome and is therefore inherited through the paternal line; looking at gender

CODIS

DNA database

NGI

Next Generation Identification; using palm print, iris color, facial freckles, hair color, etc. to identify individual

forensic genealogy

using genetic information to identify suspects

genotyping

the genetics of an individual

phenotyping

observable characteristics resulting from the interaction between genotype and the environment

degredation

starting to break down

cross contamination

the process by which bacteria or other microorganisms are unintentionally transferred from one substance or object to another

mutation

change in a DNA sequence that affects genetic information