1. Looking for Evidence at the Crime Scene
Notes 1.3

2. Fourth Amendment
The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizure, shall not be violated, and no warrants shall issue, but upon probable cause, supported by oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.

3. Part 1. Search and Seizure Laws
Evidence can be collected
With a search warrant signed by a judge
Must state:
Probable cause
Where, and hours
What searching for

4. Search and Seizure Laws
Evidence can be collected
Without a search warrant if the officer sees a crime in progress

5. Search and Seizure Laws
Evidence can be collected
Without a search warrant if the integrity of the evidence is in jeopardy, or
When there is consent.

6. The Chain of Custody
A complete record of who has the evidence at every moment from collection to courtroom must be kept.

7. Part 2. How to Find Evidence….
Strip/Line Method
Grid Method
Zone/Quadrant Method
Spiral Method
(see Chapter 2, page 37in Textbook)

8. when looking for relatively small objects
Strip or Line Method
start
Good for small areas
when looking for relatively small objects

9. Grid Method
start
Good for small areas when looking for very small objects that might be missed by a single searcher

10. Zone or Quadrant Method
Good for areas when the relationship between pieces of
evidence is important (firearm trajectory, blood spatters…)

11. Spiral Method Good for very large areas
when looking for relatively large objects

12. Part 3. How to Measure Evidence….
Rectangular Coordinates
Triangulation
Transecting Baseline
GPS (polar coordinates)
Secondary reference points

13. Rectangular Coordinates
measurements are taken from the two nearest perpendicular walls

14. Triangulation
Measurements are taken from the two fixed reference points

15. Transecting Baseline
Measurements are taken from and along a metal tape placed at a central location

16. GPS (polar coordinates)
Measurements are taken using a global positioning satellite

17. Secondary Reference Points
Measurements to evidence item are taken from the location of other evidence items

18. Which method is best for…
1. looking for bullet casings in a drive-by shooting?
2. looking for a missing person lost in the woods?
3. looking for fingerprints in a bank robbery?

19. Your Assignment
Today/Tomorrow you will be presented with a small “crime scene”. You will need to locate the five items of evidence, triangulate them from two adjacent corners and determine their size. In addition you will need to record the size of the “room” and the location of the “door”.
Create a data table (s) to record the information.
Create a possible scenario to help explain the circumstances.