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?

1. Besides the use of dental impressions to identify a person, DNA analysis is also being done on teeth. What part of the tooth could contain DNA? Explain your answer. 2. Refer to the diagram of adult teeth in your text and your dental impressions. Based on the structure of the teeth, what do you

1. Summarize the importance of technology in tool mark examination and analysis for the courtroom. Include at least two different technologies in your summary. 2. Distinguish between the following types of marks found on a surface: abrasions, cuts, and indentations.

1. List the characteristics that helped you distinguish the different types of tools. 2. The tool mark impression that matched the crime scene was number _____ owned by ______. 3. Would there be sufficient evidence for an arrest? Why or why not?

Instead of working with photographs, use four different screwdrivers to prepare tool impressions. Select one screwdriver to be the crime-scene tool and prepare an impression on a piece of soft wood (like pine) to serve as crime-scene evidence. Take photographs and measurements, and prepare a cast of the tool impressions. Prepare your testimony as an