Do further research on imprint or impression evidence in the O.J. Simpson or Ted Bundy cases, or research case studies not mentioned in the text that had their cases resolved as a result of impression or imprint evidence. Submit a written report on your findings.

Tire impressions of a tire must be made using the complete rotation of a tire. Explain why this is important if the tire impression is to be compared with a photograph of a tire impression found at a crime scene.

Describe how you could distinguish the teeth of an adult from the teeth of a teenager or child. Dispose of unused Plaster of Paris in a garbage container; do not dump it down the sink drain!

Thoroughly wash all equipment as soon as possible after use. After dumping out any excess Plaster of Paris, allow the remaining plaster to dry. The old plaster can be removed after it dries by pounding on the sides of the plastic coffee can.

Work outside if conditions permit. If you are working inside, use newspaper to line any desktops. The sand can scratch the surface of some countertops. Wear safety goggles when mixing Plaster of Paris and when using the hairspray. The spray can also irritate some people’s throat and nasal passages.

1. Why do crime-scene investigators build a frame around the shoe print before casting? 2. What was the purpose of spraying with the hair spray? 3. Why is it important to brush the excess sand from the plaster casting?

Shoe prints can be obtained in the winter from snow, but Plaster of Paris cannot be used. What would happen if you tried to produce a cast of an imprint in snow using Plaster of Paris? Why are footprints easier to cast than tire tracks?

With the tire marks and measurements, the crime-scene investigator will be able to help reconstruct the accident. Information about the hit-and-run car can be obtained from the tire mark measurements. Just like fingerprints at the scene of a robbery can incriminate a suspect, tire marks at an accident can also incriminate a driver.

Sometimes the drivers may not recall what happened, or the story they tell the police may be somewhat altered to try to protect themselves from getting a ticket or a jail sentence. When accident scenes are reconstructed using tire marks and measurements are made at the scene of the accident, the tire marks do indeed

1. Measurements can be taken of dental patterns and bite marks. List what characteristics make dental patterns unique. 2. Explain how a dental impression provides clues to someone’s age. 3. How would obtaining dental records help in the identification of unknown bodies?