1. All rights Reserved
Cengage/NGL/South-Western © 2016

2. FORENSIC SCIENCE Application of science to the law
Society is dependant on rules of law
Applies knowledge and technology to enforcement of laws
Science is used to help solve the argument in the criminal justice system
Science is accurate and objective

3. FORENSIC SCIENCE
The application of science to those criminal and civil laws that are enforced by police agencies in a criminal justice system
This course
Chemistry, Biology, Physics, and Geology useful for determining evidential value of crime scene and related evidence

5. FORENSIC SCIENTISTS Aka criminalist Can appear for either side
Can appear in criminal or civil matters
Tend to present findings in written reports
Can attend and testify in person
Give objective opinion of evidence analysis
Integral part of criminal justice system
TV shows
Juries expect forensic scientists to be experts in all areas now because of TV shows like CSI

6. TYPICAL INVESTIGATION
Crime scene investigators
Gather evidence from:
Crime scene
Suspect
Victim
Forensic Scientists
Examine evidence
Provide scientific findings

7. PHYSICAL EVIDENCE Articles of materials
Found in conjunction w/a criminal investigation
Assists in identifying the suspect or in determining the circumstances under which a crime was committed
Sources of Physical Evidence:
Crime scene
Suspect(s)
Victim(s)

9. HOW AN ITEM BECOMES PHYSICAL EVIDENCE
Before an object can become evidence, it must be recognized by the investigator as having a relationship to the crime committed

10. EXAMPLES OF PHYSICAL EVIDENCE
BLOOD
HAIR
FIBERS
PAINT
GLASS
FIREARMS EVIDENCE
IMPRESSIONS
FLAMMABLE SUBSTANCES
ETC.

11. Types of Evidence Direct evidence Circumstantial evidence
First-hand observations
Circumstantial evidence
Indirect evidence that can be used to imply a fact but that does not prove it

13. Types of Evidence (continued)
Class evidence
Narrows an identity to a group of persons or things
Individual evidence
Narrows an identity to a single person or thing

14. Packaging Evidence
The paper bindle is ideal packaging for small, dry, trace evidence.

15. SCIENTIFIC REQUIREMENTS OF PHYSICAL EVIDENCE
Adequate sample must be provided
Sufficient standards (knowns) must be provided
Sample integrity must be maintained

16. INVENTORY Physical evidence inventory Case Reference data Item number
Brief description
Where found
Witnesses
Serial numbers (if any)

17. GENERAL MARKING PROCEDURES
LARGE SOLID OBJECTS
MARK WITH INITIALS
SMALL SOLID OBJECTS
PLACE IN CONTAINER AND SEAL
LIQUIDS
KEEP IN ORIGINAL CONTAINER
SEAL AND MARK

18. CHAIN OF CUSTODY RULE
The party seeking to introduce into evidence the results of examination of evidence has the burden of proving that the specimen or object is in fact derived from or taken from the particular person or place.
This proof is customarily shown by testimony which traces the location and custody of the specimen.

19. CHRONICLE OF CUSTODY THE STEPS IN THE CHAIN INCLUDE
THE INITIAL POSSESSION BY AN OFFICER
THE METHOD OF STORAGE
THE JOURNEY TO THE LAB
THE METHOD OF STORAGE AT LAB
THE POSSESSION OF UNUSED PORTION UNTIL PRESENTED IN COURT

20. Chain of Custody

21. Edmond Locard ( )
Demonstrated how Gross’ principles could be incorporated into workable laboratory
Educated in Medicine and Law
1910 Lyons Police Dept. gave two rooms and two assistants to start police laboratory
Initially had microscope and spectrometer
Founder and Director of Institute of Criminalistics at the University of Lyon

22. Principle of Exchange Locard's Principle of Exchange
When a person comes in contact with an object or another person, a cross-transfer of physical material can occur.
The intensity, duration, and nature of the entities and contact determine the extent of the transfer.

23. “Golden Rule” of Crime Scene Investigation /Management
“Never touch, change, or alter anything until it has been documented, identified, measured, and photographed … when a body or article has been moved, it can never be restored to its original position”

24. The Seven S’S of Crime-Scene Investigation
Securing the Scene
Separating the Witnesses
Scanning the Scene
Seeing the Scene
Sketching the Scene
Searching for Evidence
Securing and Collecting Evidence

25. FIRST OFFICER AT SCENE ADMINISTER FIRST AID ARREST PERPETRATOR
REQUEST AID
DETAIN AND IDENTIFY WITNESSES
SAFEGUARD CRIME SCENE

26. STEPS FOR SAFEGUARDING THE SCENE
DETERMINE CRIME SCENE AREA
EXCLUDE ALL PERSONS
BLOCK OFF BOUNDARIES
IDENTIFY AND SEGREGATE WITNESSES
NOTE DETAILS FOR LATER
AVOID UNNECESSARY WALKING ABOUT
DON’T TOUCH ANYTHING
PROVIDE INFORMATION TO INVESTIGATORS

27. RECORD THE CRIME SCENE
Photography
Sketching
Notes