skills csi

algor mortis

The cooling of the body after death 30mins-1hour

blank samples

A control sample used to check for contamination or issues with the final sample

bindle paper

A folded piece of paper used to transport evidence like hairs or powders

chain of custody

Documentation of evidence from time of collection to time of disposal

circumstantial evidence

Evidence that doesn’t directly prove the claim but leads to it (an eye witness, the suspects body language, fingerprints)

comparison samples

Comparing known sample (a victim or suspects actual hair) with evidence found on scene (to see if they match)

control samples

Known substances of origin used to check accuracy and a standard of comparison

• triangulation method, rectangular coordinate method, transecting baseline coordinate method, polar coordinate method

Crime scene measuring techniques

• overall, midrange, close-up

• Crime scene photographs

• grid search, spiral search, lane/strip search, zone search

• Crime scene search methods

direct evidence

Direct proof of a fact without interference or presumption

elimination samples

Samples from people lawfully involved with the scene to help cross out contamination

exculpatory evidence

Material or information that protects a suspects innocence (proving, excusing, justifying their innocence)

faraday bags

Bags that block out electromagnetic signals protecting phones collected from suspects from being hacked or interfered with.

forensic archaeology

Study of human remains from a scene

forensic entomology

Study of insects on a crime scene helpful to determine time of death

forensic odontology

Study of dental health from a crime scene

-can determine: sexual assault, bite marks, and the victim/suspect identity

forensic pathology

Study of determining cause of death

• Fruit of the Poisonous Tree Doctrine

All evidence collected illegally is deemed admissible (not valid) in a court of law

inculpatory evidence

Any evidence that connects a person to a crime either directly or indirectly

latent fingerprints

Fingerprints transferred from oils and moisture on the skin to a surface

• NDIS/CODIS

National database of DNA profiles managed by the FBI

oblique lighting

Illuminating a subject from an angle rather than directly above or below

patent fingerprints

Fingerprints easily seen by the naked eye that don’t require special techniques for development

• Post-mortem lividity (livor mortis)

The pooling of blood in the dependent parts of the body after death due to gravity, causing a discoloration of the skin that can vary from pink to dark purplish

Visible within 2-4 hours, maximum in 8-12

PPE

Specialized clothing or gear worn to minimize exposure to hazards (gloves, masks, etc)

presumptive test

Preliminary screening used to identify the possible presence of a substance

prioritization of evidence collection

Fragile/biological evidence first, trace materials (small, often microscopic, materials that can be transferred during contact between individuals or between an individual and an environment), then other evidence

processing/collection methods

Visual inspection, photography, and various collection techniques depending on the type of evidence

• Proper packaging of various types of evidence (drugs, biological material, firearms, knives, etc.)

Drugs - clear, sealed plastic bags with an inner container to prevent leakage

Biological - paper bags/boxes to allow airflow

Firearms - unload and secure with plastic ties, placed in box or container

Knives - cardboard boxes to prevent puncture

Trace evidence - use paper bindles to secure, then place inside plastic bags

Fire debris - airtight glass/metal containers

reference samples

Known, verifiable samples used for comparison with unknown samples found at a crime scene

rigor mortis

The stiffening of muscles after death

Begins in 2-3 hours, ends in 6-12, lasts for 12-24 until muscles relax

routes of exposure

Inhalation, ingestion, skin/eye contact, etc

probable cause

enough reason to believe a crime was committed

reasonable suspicion

a reasonable guess that someone might be doing something illegal

proof beyond a reasonable doubt

almost certain a person did something

preponderance of the evidence

more than 50% likely to be true

• probable cause, reasonable suspicion, proof beyond a reasonable doubt, preponderance of the evidence

standards of proof

statutory/common law

Common law is based on past judicial opinions, statutory law is based on current written laws

transient evidence collection

Evidence that can degrade quickly, often collected by taking photographs as soon as possible