Presentation on theme: "Mr. Chapman Forensics 30. Direct Evidence – includes firsthand observations such as eyewitness accounts or police dashboard video cameras. Direct."— Presentation transcript:
Direct Evidence – includes firsthand observations such as eyewitness accounts or police dashboard video cameras. Direct evidence includes what witnesses said, heard, or did, and confessions are included as direct evidence.
Circumstantial evidence – indirect evidence that can be used to imply a fact but that DOES NOT DIRECTLY PROVE IT. Circumstantial evidence on its own is almost NEVER enough to directly convict a person of committing a crime.
TRACE evidence is a form of circumstantial evidence, and the one that most people are the most familiar with. CIRCUMSTANTIAL evidence can be found in one of two ways:
Physical Evidence: includes fingerprints, footprints, shoe prints, tire impressions, and tool marks. Generally, physical evidence reduces the number of suspects to a very small group. Exception: Fingerprints are generally as condemning as forms of biological evidence.
Biological Evidence: includes body fluids, hair, plant parts, and natural fibres. Biological evidence is typically the most persuasive type of evidence in court, as it can narrow the suspects to an extremely small group of people, or even one individual.
Class evidence: narrows an identity to a group of persons or things. For example, if Type A blood is found at the scene, that narrows the group of suspects to anyone with Type A blood. Individual evidence: narrows the field to a single person or thing. A fingerprint is an example of individual evidence.
Usually the first to arrive at a crime scene. May require that a district attorney be present to determine whether a search warrant is necessary for the crime-scene investigators.
Document the crime scene in detail and collect physical evidence. CSIs include: Recorders: to record the data Sketch artists: to sketch the scene
Photographers: to take photos of the crime-scene. Other, general evidence collectors.
Medical Examiners: also known as coroners, and may be necessary to determine the cause of death. Detectives: look for leads by interviewing witnesses and talking to the crime-scene investigators about the evidence. Notice that the CSIs don’t do this!
Entomologists Forensic scientists Forensic psychologists All these specialists may be consulted if their expertise are required.
1. What type of evidence most closely resembles individual evidence – physical or biological? 2. What are two different types of crime- scene investigators? 3. What is a detective’s role at a crime- scene?