Name ____________________________________ Period__________ Date______________

Trace Evidence

Directions: Open this document on to access the websites.

Use the websites on the Trace Evidence and MoreForensic Science Links (page 2) of the Kid Zone at: to complete this worksheet.

Site A: Wikipedia – Locard’s Principle 

On the Wikipedia site, click on the Dr. Edmund Locard link,

Use the excerpt from the article to answer the question.

Use Ziploc bags for items, such as nuts and bolts, that won’t be processed further. Keep different sized bags on hand, since you want to match the item to the bag.

Paper should be used for items that need to breathe. Fingerprint evidence, pillows, comforters, etc. go in paper. Wet items go into paper. If you seal a bloody shirt in a Ziploc, it will putrefy and be ruined. Put bloody clothing into paper bags and transport to your station. While it’s drying, place white paper bags under the clothing to collect any trace evidence that falls. Retain the transport bag and white paper bags as evidence. Green marijuana also needs to go in a paper bag; if sealed in plastic, it will mold and won’t test properly.”

Site B: AC Trace Evidence 

Site C: Hair Detective:

Use this site instead of the one on the web page.

  1. Scientists have found a way to use hair to figure out where a person is _________________ and __________________that person _____________________.

  1. How do scientists use tap-water to figure out where a person is from?

  1. How did scientists test to see if their idea would work? Did it?

  1. True or False: The new technique can point to exactly where a person is from.

  1. How do authorities use the information to solve crimes?

  1. What advice is given by the scientists to the criminals?