HOSA - Forensic Science - Notes (copy)

Chain of Custody

The document and unbroken transfer of evidence.

Circumstantial Evidence

(Indirect Evidence) evidence used to imply a fact but not prove it directly.

Class Evidence

Material that connects an individual or think to a certain group.

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.

Sub-Datum Point

One of several preference (reference?) points to known coordinates marked from a measurable distance and direction from the datum point.

Trace Evidence

A 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.

Locard’s Exchange Principa

States that when a criminal comes into contact with an object or person, a cross-transfer of evidence occurs.

Seven S’s of Crime Scene Investigation

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

Allele

An alternative form of a gene.

Combined DNA Index System (CODIS)

The FBI’s computerized criminal DNA database as well as the software used to run these databases; includes the National DAN Index System (NDIS).

DNA Phenotyping

The prediction of physical appearance based only on DNA.

DNA Profile (Fingerprint)

Pattern of DNA fragments obtained by analyzing a person’s unique sequence 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.

Forensics Genealogy

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

Intron

Portion of a gene that is not expressed.

Karyotype

A picture that is paired homologous chromosomes in a cell.

Kinship

Closely related individuals.

Polymer

A long molecule composed 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.

STP Markers

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

Agglutination

Clumping of microorganism or blood cells, typically die 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 and 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 are 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 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 Substance Act

Law that established penalties fro 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.

Agonist Drugs

Drugs that cause effects.

Antagonist Drugs

Drugs that lbock effects.

Associative Evidence

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

Base Principle of Toxicology

Chemicals safe in a small dose become deadly in high dosages.

Biological Evidence

Human Tissue used for identification.

Carcinogens

Causes cancers

Chemical Evidence

Seized drugs, toxicological samples, explosives.

Chemical Excretion by Means of

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

Circumstantial Evidence

Allows for the acceptance of the fact but the need for inference.

Class-Characteristic Evidence

Doesn’t reference a perticular suspect.

Criminalistics

Analysis of physical evidence.

Direct Evidence

Information established directly that requires no inference.

Dose-Response Tests

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

A Drug’s Half Life

Time in which drug decreases by 50 percent in blood.

Drugs Enter the Body by:

Ingestion, inhalation, injection, skin application, and suppository.

Enterohepatic Circulation

Process between liver, small intestine, and bile.

Exculpatory Evidence

Presence will exclude a person and exonerate

Firearm and Tool Mark Evidence

Type of impressions, bullets, and/or shells.

Fluoride, Lead, and Strontium Chemical

Stored in bone

Forensic Antropology

Analysis of bodily reamains

Forensic Entomology

Analysis of insects on dead bodies to determine time of death.

Frye Standard

New methods must be accepted by those in the field.

Immediate Cause of Death

Body problem that caused death.

Impression Evidence

Footwear, tire imprints.

Inculpatory Evidence

Presence will include a person and incriminate.

Individual-Characteristic Evidence

Associates particular individual with the commission of a crime.

Lipohilic Chemical

Stored in fat cells, released in blood stream.

Locard’s Exchange Principle

Every contact leaves a trace and a transfer of materials.

Manner of Death

Homicide, suicide, natural, accident, and undetermined.

Myocardial Infraction

Heart attack

Pharmacodynamics

Mechanisms that cause physiological and pathological changes.

Pharmacologist

Studies natural and synthetic chemicals.

Pharmacokinetics

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

Plasma Protein chemicals

Released slowly into cells.

Proximate Cause of Death

What led to the immediate cause of death.

Questioned Documents

Handwriting analysis, alteration, obliteration, and erasures.

Toxicologist

Studies toxic effects of chemicals.

Trace Evidence

Suspect will leave and take something at the scene.Xen

Xenobiotics

Chemicals foreign to the body.