Download presentation
Presentation is loading. Please wait.
Published byHugo Holt Modified over 9 years ago
1
Do Now: get handout and paper bag Take out HW Work on the Q’s below: Agenda: Collection of evidence Types of Evidence HW: Sock prelab Prep lab notebook
2
Let the evidence speak for itself. Presentation developed by T. Trimpe 2006 http://sciencespot.net/
3
Source: http://www.virtualsciencefair.org/2004/fren4j0/public_html/trace_evidence.htm "Every Contact Leaves a Trace" The value of trace (or contact) forensic evidence was first recognized by Edmund Locard in 1910. He was the director of the very first crime laboratory in existence, located in Lyon, France. The Locard’s Exchange Principle: "with contact between two items, there will be an exchange." For example, burglars will leave traces of their presence behind and will also take traces with them. They may leave hairs from their body or fibers from their clothing behind and they may take carpet fibers away with them.
4
How does the textbook define physical evidence? Physical evidence is any object that can establish that a crime has been committed or can link a crime and it's victim or a crime and it's perpetrator. Forensic science starts at the crime scene where evidence is recognized and properly preserved.
5
1.Photography (www.mycrimekit.com)www.mycrimekit.com 2.Sketches 3.Conduct a systematic search for evidence 4.Collect physical evidence 5.Maintain the chain of custody 6.Obtain standard reference samples 7.Submit evidence to the laboratory
6
EVERY person who has come into contact with the evidence handled examined Acts as a “paper trail” Failure to do so: lead to questions regarding the authenticity and integrity of the evidence and the examinations When evidence is is analyzed there must be a new seal made
10
Procedures Identify the evidence (is it evidence, could it contain evidence?) Decide which type of packaging would be the most appropriate (plastic pill bottle, manila envelope, paper bag, a sealed container?) Record where evidence was found (living room, northeast corner of park, etc.) Label the evidence (victim’s shirt, hat) Date and intial (you will keep a record of when you collected the evidence and that you collected)
11
Tag the evidence for identification Seal the evidence (put tape on it to make sure no one else has opened/compromised the sample) Fill out an evidence submission form Maintain records on chain of custody Every person that handles the evidence needs to log it.
12
Paint Glass Explosives Ballistics Dust & Dirt Impression evidence Fracture matches Wounds Questioned documents Insects DNA Skeletal remains Body fluids Hairs & Fibers
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.