Types of Evidence
What principle states that when a person comes into contact with an object or another person, there is a cross-transfer of evidence?
Locard’s Exchange Principle
What is the first step of crime scene investigation?
Securing the Scene
What are the first two priorities of the first officer at a crime scene?
Provide medical aid and arrest suspects.
What is the most important rule before photographing a crime scene?
The scene must be unaltered
Which search pattern works best for large, outdoor areas like fields?
Line/Strip Method
What is the chain of custody?
A chronological paper trail documenting control, transfer, and analysis of evidence.
This type of evidence is based on firsthand observations like eyewitness testimony or video surveillance.
Direct Evidence
Why are witnesses separated during an investigation?
So they don’t influence each other’s accounts.
Why is it important to control who enters and exits the crime scene?
To prevent contamination or tampering of evidence.
What are the three angles used when photographing evidence?
Close-up, Mid-range, Long-range
Which search pattern is best for buildings or areas with multiple rooms?
Zone/Quadrant Method
Why must each piece of evidence be packaged separately?
To prevent cross-contamination
What is the difference between class evidence and individual evidence? Give one example of each
Class narrows to a group (ex. blood type), Individual narrows to one person/item (ex. fingerprints).
Which step involves a quick scan to mark evidence with markers before detailed work begins?
Scanning the Scene
What information must be included on a crime scene log?
Everyone entering/exiting with time and date recorded.
Name three areas that must be photographed at a crime scene.
Crime area, Adjacent areas, Points of entry/exit, Body (any three).
This search pattern has investigators move inward or outward in a circular pattern
Spiral Method
What type of container should be used for biological evidence like bloodstained clothing?
Paper bags, packaged separately.
This type of evidence is temporary and easily lost or changed, like odors, temperatures, or footprints in mud.
Transient Evidence
Which step uses search patterns like grid, zone, spiral, or line to locate all evidence?
Searching the Scene
What could happen if the crime scene isn’t secured properly?
Evidence may be contaminated or inadmissible in court.
What is triangulation used for in crime scene sketches?
Measuring distance from two fixed points to accurately place evidence.
Which search pattern provides double coverage and is the most thorough?
Grid Method
What is a bindle (druggist’s fold) used for?
Securing very small evidence like powders or hair.
Is a hair WITH the root attached class or individual evidence, and why?
Individual evidence because DNA is present in the follicle.
Put these steps in order: Sketching, Securing, Scanning, Seeing.
Securing → Scanning → Seeing → Sketching
This is the first task investigators complete after the scene is secure and witnesses are separated.
Taking photographs
What should investigators do if they discover evidence was moved before it was photographed?
Note that the object was moved, but do not put it back in the scene.
Why is it important to document where each piece of evidence is found?
To maintain accuracy and integrity for court.
Give one example of how the chain of custody could be broken and why that is a problem.
Re-opening and re-sealing original packaging instead of using new packaging → evidence becomes inadmissible in court.