Chapter 2 and 3 Evidence and Crime Scene Evidence 2 types: Testimonial evidence – where a statement is made under oath in court by a witness, can be called direct evidence or prima facie evidence. Physical evidence – tangible items that tend to prove some material fact, also called real evidence, ex: documents, other objects.

Types of physical evidence: Drugs plastics fingerprints plants hair, fibers Paints tissues soil serial numbers bones glass explosive residues Firearms pollen ammunition documents feathers Wood material fluids body Rubber material Impressions (shoe prints, bite marks, tool marks) alcohols (especially ethanol) Petroleum products

Indirect evidence – evidence providing only basis for inference about the disputed fact. Circumstantial evidence – evidence based on suggestion rather than personal knowledge or observation.

Physical evidence can: Prove Back up testimony Link suspect with crime Determine id Reconstruct crime

Individual Evidence – material that can be related to a single source, always involves a comparison. Class evidence – material that can be associated only with a group of items that share properties or characteristics.

You decide? Which type of evidence is it? Bite mark Tire track Fingerprint Earring left behind at the scene Shoe print showing popular brand of shoe Hair Individual, class, individual, individual, class, class

Chapter 3 Crime Scene – Any place where evidence may be located and gathered to help explain events. Modus operandi – the characteristic method of operation of a criminal, sometimes referred to as MO.

STEPS TO PRESERVE AND ISOLATE THE CRIME SCENE 1. First officer on scene: Secure the scene – make sure perp is not on still at crime scene get medical assistance save lives even at the expense of evidence make arrest.

2. Protect scene - from unauthorized people, suspect and witnesses must be detained.

3. Document the Scene: Notes – include: date, time, and description of location, weather, environmental conditions, names of all people involved, witnesses, and victims. Photographs or videotape – entry and exit, evidence, all angles, include ruler scales. Sketches – give a better overall layout of the scene; give measurements, scale and relative placement of all important details.

4. Search for Evidence: Line/strip is used outside – people form a line shoulder to shoulder and walk through the area. Grid – double line search – officers move parallel to each other and then repeat the sweep from different direction.

Zone – House or buildings – each team is assigned a room or floor to search. Wheel/ray – small areas – begins at the center of the scene and move outward in a pattern that makes a circle. (spiral )

Collect and package the evidence: (tag and bag it)

6. Maintain Chain Chain of custody a written record of all people who have had possession of an item of evidence.

7. Obtain controls – compare with known standard or control all items of evidence if possible

8. Submit evidence to the lab

Wear latex gloves, shoe covers Goggles, face shield 9. Safety Wear latex gloves, shoe covers Goggles, face shield Be alert to sharp objects, knives, ect Maintain red biohazard plastic bag for disposal Note taking Disinfect No eating, drinking, smoking Disposal of clothing items

10. Reconstruction – supports a likely sequence of events by the observation and evaluation of physical evidence as well as statements made by witnesses and those involved with the accident.