HOSA Forensic Science

chain of custody

the documented and unbroken transfer of evidence

class evidence

material that connects an individual or thing to a certain group

crime-scene investigation

a multidisciplinary approach in which scientific and legal professionals work together to solve a crime

crime scene reconstruction

a hypothesis of the sequence of events from before the crime was committed through its commission

datum point

a permanent, fixed point of reference used in mapping a crime scene

direct evidence

evidence that (if true) proves an alleged fact, such as an eyewitness account of a crime

individual evidence

a kind of evidence that identifies a particular person or thing

subdatum point

one of several preference points of known coordinates marked from a measurable distance and direction from the datum point

trace evidence

small but measurable amounts of physical or biological material found at a crime scene

Triangulation

a technique used to record evidence location from two fixed reference points

Seven S's of Crime Scene Investigation

secure the scene , separate the witness, scan the scene, see, sketch, search, secure evidence

Mapping the Outdoor Crime Scene

Check pg. 32

Analyzing Evidence

See pg. 34

Staged Crime Scene

See pg. 35

Summary, Case Studies, Careers, and Review

See pgs. 36-42

allele

An alternative form of a gene.

Combined DNA Index System (CODIS)

the FBI's computerized criminal DNA databases as well as the software used to run these databases; includes the National DNA Index System (NDIS)

DNA Phenotyping

The prediction of physical appearance based only on DNA

DNA profile (fingerprint)

patter of DNA fragments obtained by analyzing a person's unique sequences of noncoding DNA

DNA profiling

a technique used to identify a person based on analysis of their genetic code

electrophoresis

a method of separating molecules, such as DNA, according to their size

Exon

portion of gene that is expressed

Familial Searching

using CODIS and state databases to search for relatives of unknown persons or offenders

Forensic genealogy

using both CODIS and public databases to identify a subject by comparing their DNA to one or more family members

Intron

portion of a gene that is not expressed

karyotype

a picture of the paired homologous chromosomes in a cell

kinship

closely related individuals

polymer

A long molecule composedd of similar repeating units

polymerase chain reaction (PCR)

a method of amplifying (duplicating) tiny amounts of DNA evidence for use in investigations

polymorphism

region of repeating DNA within an intron that is highly variable from person to person

primer

a starting sequence added to trigger replication of a specific section of DNA or RNA

short tandem repeats (STRs)

sequence of repeating bases in noncoding regions of DNA that are used in DNA profiling

single nucleotide polymorphism (SNP)

a type of genetic variation where one nucleotide is substituted for another

STR markers

a gene or DNA sequence with a known location on a chromosome

Agglutination

Clumping of microorganisms or blood cells, typically due to an antigen-antibody interaction.

Angle of Impact

angle at which blood strikes a target surface relative to the horizontal plane of the target surface

antigen

substance that triggers an immune response

area of convergence

a two-dimensional view of the intersection of lines formed by drawing a line through the main axis of at least two drops of blood that indicates the general area of the source of the blood spatter

area of origin

the location of a blood source viewed in three dimensions as determined by projecting angles of impact of individual bloodstains

Cast-off pattern

blood projected onto a surface as a result of being flung from an object in motion

passive drop

blood drop created solely as a result of gravity

satellite

smaller droplets of blood projected from larger drops of blood upon impact with a surface

spine

elongated blood streaks radiating away from the center of a bloodstain

swipe

blood pattern resulting from a lateral transfer from a moving source onto another surface

wipe

smeared blood pattern created when an object moves through blood that is not completely dried

acute poisoning

a high dose over a short period of time

Chronic poisoning

Low dose over a long period of time

Controlled Substances Act

law that established penalties for possession, use, or distribution of illegal drugs and established five schedules for classifying drugs

First Step Act

a law that reduced the penalties of drug use, possession, and distribution for those already in federal prison

Metabolite

the by-product formed during the metabolism of a chemical

..

Criminalistics

Analysis of physical evidence

Forensic anthropology

Analysis of bodily remains

Forensic entomology

Analysis of insects on dead bodies to determine time of death

Pharmacologist

Studies natural and synthetic chemicals

Carcinogens

Causes cancers

Toxicologist

Studies toxic effects of chemicals

Base principle of toxicology

Chemicals safe in small dosages become deadly in high dosages

Dose-response tests

Effects of drugs at different dosages for the relationship between dose and effect

Pharmacodynamics

Mechanisms that cause physiological and pathological changes

Pharmokinetics

How the chemical is absorbed, distributed, metabolized, and excreted

Drugs may enter the body by

Ingestion, inhalation, injection, skin application, suppository

Lipophilic chemials

Stored in fat cells, released into blood stream

Plasma protein chemicals

Released slowly into cells

Fluoride, lead, and strontium chemicals

Stored in bone

Xenobiotics

Chemicals foreign to the body

Chemical excretion by means of

Feces, sweat, saliva, breast milk, nails, and hair

Enterohepatic circulation

Process between liver, small intestine, and bile

A drug's half life

Time in which drug decreases by 50% in blood

Agonist drugs

Drugs that cause effects

Antagonist drugs

Drugs that block effects

Immediate cause of death

Body problem that caused death

Proximate cause of death

What led to the immediate cause of death

Manner of death

Homicide, suicide, natural, accident, undetermined

Myocardio infarction

Heart attack

Frye standard

New methods must be accepted by those in the field

Inculpatory evidence

Presence will include a person and incrminate

Exculpatory evidence

Presence will exclude a person and exonerate

Direct evidence

Information that establishes directly and requires no inference

Associative evidence

Evidence that will link a person to a place (hair, blood, paint, bullets, fingerprints)

Class-characteristic evidence

Doesn't reference a particular suspect

Individual-characteristic evidence

Associates particular individual with the commission of a crime

Biological evidence

Human tissue used for identification

Chemical evidence

Seized drugs, toxicological samples, explosives

Trace evidence

Suspect will leave and take something at the scene

Impression evidence

Footwear, tire imprints

Firearm and tool mark evidence

Type of impression, bullets, shells

Questioned documents

Handwriting analysis, alteration, obliteration, erasures,

Who helped advance fingerprint, firearms, and hair analysis?

Victor Balthazard

Who was credited with developing a probablility model that showed fingerprints are unique (10^60 chance of 2 people having same patterns)?

Victor Balthazard

Who developed an advanced photographic method of comparing markings on bullets?

Victor Balthazard

What is the identification of suspects using 11 body measurements?

Anthropometry/bertillonage

Who created anthropometry?

Alphonse Bertillon

When was anthropometry popular?

1883-1900s

Who was the first forensic scientist that used fingerprints to solve a case?

Alphonse Bertillon

Who was the cousin of Charles Darwin?

Sir Francis Galton

Who developed the first classification for fingerprints?

Sir Francis Galton

What is used to describe one of the features found in fingerprints in the US?

Galton Ridge

Who is credited with establishing examination of firearms evidence in US?

Galvin Goddard

Who coined the term of "criminalistics"?

Hans Gross