Forensic Science Experiments in Your Own Crime Lab by Robert Gardner

Author:Robert Gardner
Language: eng
Format: epub
Publisher: Enslow Publishing, LLC

EXPERIMENT 5.1

Teeth Impressions

YOU WILL NEED

•SCISSORS

•STYROFOAM CUPS

•MARKING PEN

•FAMILY MEMBERS, FRIENDS, OR CLASSMATES

•LARGE PIECE OF CHEESE OR HARD CHOCOLATE

1.Using scissors, cut square pieces about 8 cm (3 in) on a side from Styrofoam cups. Put two pieces, one on top of the other, into your mouth. Bite down firmly on the Styrofoam pieces. Remove them from your mouth.

2.Label the top piece “Upper” and the lower piece “Lower.” Compare the impressions. How can you distinguish the impressions made by the upper teeth from those made by the lower teeth?

3.Collect teeth impressions from family members, friends, and classmates. Label the top and bottom teeth marks and the name of the person who made the impressions.

4.In your absence, ask that one of your friends or a family member whose teeth impressions you have on file take a bite out of a large piece of cheese or hard chocolate. Using the Styrofoam impressions you have collected, can you identify the person who bit the cheese or chocolate?

Teeth impressions have been used to solve a number of real crimes. In one case, detectives found a wad of chewing gum with teeth marks at the scene of a murder. A forensic dentist made casts of the impressions by applying silicone to the hardened gum. The teeth that chewed the gum did not match the teeth of the victim; however, they did match impressions taken from a suspect. Forensic scientists were able to collect enough saliva from the gum to determine the blood type of the chewer. It was type AB blood, which is found in only 4 percent of the population, but it matched the suspect’s blood type. Facing both pieces of evidence, the suspect confessed to the crime.

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.