Crime Scene Processing and Physical Evidence Answers

Answers to select End of chapter Review questions Answers to Review questions (pg 78) Multiple Choice 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. A A C C B True/False Statements False False True False False What is physical evidence? Give three examples of physical evidence found at a crime scene. Physical evidence encompasses any and all objects that can establish a crime has been committed or can link a crime and its victim or its perpetrator. Examples may include: hair, skin, fibres, fingerprints, blood, DNA weapons, soil, glass and documents. 12. What is the first step in crime scene processing? Secure and isolate the scene 13. Why is it important to exclude onlooker sfroma crime scene? It is important because every individual has the potential to destroy physical evidence. 14. Name three methods for recording a crime scene and list one unique advantage of each. A. Photography- Advantage is the defintion of detail it provides B. Sketches- Record precise distances between important points in the crime scene. C.. Notes- Provide a source of detailed informationabout the scene for future reference. 15. The most important prerequisite for videorecording/photographing a crime scene is for it to be unaltered. 16. Rough sketch -draft representation …and Finished sketch.. See notes. For answers to questions # 17-23 refer text/slides.. 23. Name one type of evidence that should be stored in air- tight containers and one type that should not be stored in such a container. Explain. Charred debris recovered from scene of suspicious fire must be sealed in an airtight container to prevent evaporation of volatile petroleum residues. Items of clothing found at a crime scene should be air dried and placed individually in separate paper bags to ensure constant circulation of air through them and thus prevent the formation of mold and mildew. 24. Question on Chain of custody- Refer to lecture slides and text. 25. What is substrate control and how is it used in crime scene investigation? A substrate control is uncontaminated surface material close to an area where physical evidence has been deposited. This sample is used to ensure that the surface on which a sample has been deposited does not interfere with laboratory tests. 27. Rigor Mortis- Medical condition occurs after death and results in stiffening of body parts in the position they are in when death occurs. Livor Mortis- is a medical condition that occurs after death and results in settling of blood in areas of the body closest to the ground. Algor Mortis refers to postmortem changes that cause a body to lose heat. They are important to the forensic pathologist because they offer several ways to approximate time of death. 29. What does a forensic entomologist study to estimate time of death? Explain why such estimates are not always straightforward. A forensic entomologist studies the development of insect larvae in a body to estimate time of death. These determinations are not always straightforward because the rate at which thelarvae develop is affected by environmental influences such as geographic location, climate and weather conditions. Application & Critical Thinking ( Refer to questions in your text, pg 80) #2. Missing elements are the time, a description of type of crime, and measurements of the scene. #3. An investigator would likely collect standard/refrence samples of hair, fibres, and blood because these are the items most likely ot have been transferred from perpetrator to victim and vice- versa in a struggle. #4. Rigor mortis would be unsuitable if thevictim has been dead longer than 36 hours because the condition disappears aftr this time. Livor mortis ceases 12 hours after death, so it would be of limited value in estimating time of death after this period has elapsed. Algor mortis would not be an accurate method for estimating time of death if the body was stored in a particularly hot or cold environment because this would affect the rate at which the body lost heat. #5 a) Forensic entomologist ; b)Forensic odontologist c) forensic anthropologist