Forensics Unit 1

Define Forensics

Use of chemistry, biology, physics, and geology to determine the value of crime scene evidence

Sir Arthur Conan Doyle

Used “Sherlock Holmes” to introduce ideas such as serology, fingerprints, and firearm identification

Mathieu Orfila

Father of Toxicology

Francis Galton

Studied fingerprints and classification of prints

Leone Lattes

Discovered blood groups

Calvin Goddard

Firearm identification

Albert S. Osborn

Questioned documents and forgery

Pathologist

studies injury and disease to determine COD

Medical Examiner

determines cause, manner, and mode of death by examining corpse during autopsy

Forensic Toxicology

forensic drug analysis

Forensic Chemistry

ID and analyze toxic substances, fire accelerates, gunpowder residue, and explosives -→ also identifies poison and drugs on humans or animals

Forensic Biology

extract and analyze DNA from blood, semen, bones, body tissue, hair roots, saliva, etc.

Forensic Anthropology

Studies and examines bones in order to ID human remains and to determine age/race on remains

Forensic Entomology

Identifies unknown insects and bugs found on a decomposing body

Forensic Engineering

Determine structural failure and reconstructs events such as building collapses, train wrecks, and car accidents

Forensic Odontology

Identify human remains by matching teeth with dental records and examining bite marks

Forensic Art

Use techniques in age progression, composite imagery, facial reconstruction, and digital technology to ID missing children, criminal suspects, etc.

Forensic Psychology

Studies human psychology and behavior

Jurisprudence

lawyer specializing in forensic issues

Trace Analyst

examine hair, fibers, glass, soil, plants, minerals etc. under a microscope

Firearms Examiner

analysis of firearms, bullets, cases/shells, homemade weapons, and ammo

Forensic serology

use of biochemistry, serology, immunology, hematology, and molecular biology to ID and analyze blood and other body fluids

Responding Officer duties

secure and protect integrity of the scene, do not disturb the evidence

Crime Scene

the place where an offense has been committed and forensic evidence may be gathered

Primary Crime Scene

where criminal act occurred (homicide, suicide, etc.)

Secondary Crime Scene

where the remnants of the criminal act continue (human remains found, drugs found, etc.)

4 ways to classify a crime scene

type, condition, location, and activity

Documentation of Crime Scene

1) Determine the type of crime scene and boundaries of the scene

2) Evidence observation, collect, and analysis (weather, lights, doors, temperature, etc.)

3) Note points of entry/exit and any damage done

4) Mentally reconstruct events of crime

Physical Evidence

blood, semen, saliva, drugs, etc.

Methods of Storage of Evidence

screw capped vial, manila envelopes, pill boxes

Medical Examiner

Forensic pathologist who conducts autopsies to determine cause, manner, and mode of death

Coroner

direct investigation and let trained pathologists do the medical side

Cause of Death

specific reason why someone died

Manner of Death

broad description (natural causes, accidental, suicidal, homicidal, undetermined)

Temperature (TOD)

Will drop 1.5 degrees per hour and will bloat if undiscovered (putrefaction at 127 degrees), warm temperatures speed it up and cold temperatures slow it down

Rigor Mortis

Stiffening of body due to lack of oxygen and ATP 4 hours after death (starts at eyelids and moves down)

Livor Mortis

Discoloration of skin and pooling of blood 6-8 hours after death, gravity causes blood to pool at the lowest point

Autopsy Steps

1) weight, height, and other physical characteristics are noted

2) photographs, x-rays, light source to detect stains

3) clip fingernails and toenails for evidence

4) swab oral, anal, and vaginal cavities for evidence

5) test for gunshot residue

6) fingerprint cadaver

7) body is rinsed and head placed on stabilizing block

8) Y-incision is made

9) Internal organs are removed, weighed, and measured (samples of blood and tissue are also taken)

10) Toxicology report

11) Cut back head and peel face forward if needed

Blowfly life cycle