Crime Scene Basics
What is the first thing an officer should do when arriving at a crime scene?
What is trace evidence?
Small physical materials linking suspect, victim, or scene (hair, fiber, glass, etc.)
What does the Fourth Amendment protect against?
Unreasonable searches and seizures
Who were the victims in the O.J. Simpson case?
Nicole Brown Simpson and Ron Goldman
What is algor mortis?
Cooling of the body after death
What is created to provide an accurate, to-scale representation of a crime scene?
A finished sketch
What is the “chain of custody”?
A record showing who handled evidence and when
When can police search without a warrant?
During a lawful arrest or with probable cause
Name one way the O.J. Simpson crime scene was mishandled.
Evidence bagged together; photos without scales; used blanket from house
If a body measures 91.6°F, how long has it likely been dead?
About 7 hours (98.6 – 91.6 = 7°F drop → ~1°F/hour)
What are the “Seven S’s” of crime scene investigation?
Secure, Separate, Scan, See, Sketch, Search, Secure evidence
Why should wet evidence be dried before packaging?
To prevent destroying the evidence, mold growth, or chemical changes
What Supreme Court case involved improper evidence collection in a homicide case?
Mincey v. Arizona
Why was the O.J. Simpson case a turning point for forensic science?
Highlighted importance of proper collection and chain of custody
What is rigor mortis?
Stiffening of the muscles after death
What is the difference between a rough sketch and a finished sketch?
Rough is done at the scene (not to scale); finished is drawn to scale later
What type of container should charred debris be stored in?
Airtight/unbreakable container
Why is the chain of custody important for ethical evidence handling?
It ensures no tampering or loss of credibility
What does Frye v. U.S. relate to in forensics?
Admissibility of scientific evidence
If a body is found face-up, where will livor mortis appear?
On the back (areas touching the ground)
Give one way a crime scene can be contaminated.
Example: stepping in blood, moving evidence, using items from the scene (like the blanket in OJ Simpson case)
How can poor evidence handling lead to wrongful convictions or acquittals?
It can make evidence inadmissible or unreliable in court
What are the consequences of breaking proper forensic protocol?
Evidence exclusion, case dismissal, or wrongful verdicts
What does Daubert v. Merrell Dow establish?
Judge decides what expert scientific testimony is admissible (“Daubert standard”)
What change occurs in the eyes after death?
Fluid increases, potassium in eyes increases, clouding, film forms over the cornea