PDF Types of Evidence Lesson

q Dr. Edmond Locard § Known as the Father of Forensics § Established the first forensics laboratory in Lyon, France in 1910 § Known for Locard’s Exchange Principle qLocard’s Exchange Principle qStates that when a person comes into contact with an object (or another person), a cross-...

q Dr. Edmond Locard § Known as the Father of Forensics § Established the first forensics laboratory in Lyon, France in 1910 § Known for Locard’s Exchange Principle qLocard’s Exchange Principle qStates that when a person comes into contact with an object (or another person), a cross-transfer of physical evidence can occur qThe exchanged materials indicate that the two entities were in contact. qThis evidence bears a silent witness to the criminal act. qThe intensity, duration, and nature of the entities in contact determine the extent of the transfer. qForensics is built upon this principle. § Cross transfers create evidence. § Evidence solves crimes. Suppose this man committed a crime and is the main suspect in the case. How does Locard’s Exchange Principle apply to the injury on the suspect’s hand? qThink Pair & Share 1. Take 60 seconds to list as many pieces of evidence as you can think of that may be “trace” evidence at a crime scene. 2. Compare your evidence with a partner’s evidence. How many did you have in common? 3. Discuss where each piece of evidence may have originated from. qEvidence can be found in many forms. qInvestigators must be able to classify evidence. qAll evidence is either circumstantial or direct. All circumstantial evidence can be further classified as either physical or biological. qDirect evidence includes firsthand observations § eyewitness accounts § police dashboard § video surveillance § voice recordings Signed ransom note from the § signed ransom notes Jon Benet Ramsey Investigation § reports (toxicology, lab, etc) qCircumstantial evidence is indirect evidence that can be used to IMPLY a fact, but not directly prove it. § prints (fingerprints, bite marks, tire prints) § DNA § ballistic evidence § fibers § hair OJ Simpson’s DNA was found on the inside of these gloves that were found at the crime scene q Circumstantial evidence can be further classified: § physical: § all prints physical § bullets evidence § weapons § synthetic fibers § biological (derived from a plant/animal/person): § DNA § hair § natural fibers biological evidence q Other ways to classify evidence: § Class - narrows to a group of people/items § shoe prints § blood type § hair (w/o the root) § Individual - narrows to one individual § DNA § hair (with the root) § fingerprints Complete the Types of Evidence worksheet