Jessica Rempas

October 2, 2007

ELED 305-01

OVER HEAD PROJECTOR ACTIVITY

Life Science

Forensic Science

Who took the Book

Materials:

1.      Book

2.      Ink pad

3.      Transpierces

4.      Fingers

Safety Concerns:

Do not taste ink.

State Goals:

11.A.1b  Develop questions on scientific topics.

11.A.2b  Collect data for investigations using scientific process skills including observing, estimating and measuring.

12.A.1b  Categorize living organisms using a variety of observable features (e.g., size, color, shape, backbone).

13.B.2a  Explain how technology is used in science for a variety of purposes (e.g., sample collection, storage and treatment; measure­ment; data collection, storage and retrieval; communication of information).

Procedure:

1.      Gently put finger in ink pad.

2.      Press down on clear transpiercy.

3.      Examine results.

Questions:

1.      How do fingerprints differ?

2.      What other ways can people be identified?

3.      In what ways do you think fingerprints are used today?

Explanation:

The outer layer of skin on our fingers is made up of a series of ridges.  The ridges on each person's fingers are unique. Other personal characteristics change - fingerprints do not. Almost every time you touch something, you leave a fingerprint. Our hands are covered with sweat pores.  Sweat is often mixed with other body oils and dirt and when you touch something with your fingers, the oils and dirt on your skin stick to the surface of the object leaving an imprint of your fingertips.  Prints that you can see with the naked eye are called visible prints.  Invisible prints are called latent prints.  Most fingerprints are latent prints.  A third type of print is a plastic print.  It is a print that leaves an impression on objects such as soap or clay. A forensic scientist is interested in fingerprints as a means of identification to help solve crimes. Fingerprints offer an infallible means of personal identification. The F.B.I. has a collection of fingerprints that numbers in the millions.  Investigators often compare fingerprints from a crime scene to the fingerprints in the F.B.I. fingerprint bank to see if they can find a match and thus know who committed the crime.  They often fingerprint suspects to see if their fingerprints match those found at the crime scene.      There are three basic types of fingerprints - the arch, the whorl and the loop.

      1.      Arch patterns have lines that start at one side of the print and 

          then rise toward the center of the print and leave on the otherside of the print.

2.      Whorl patterns have a lot of circles that do not leave either side of the print.

3.      Loop patterns have lines that start on one side of the print and then rise toward the center of the print and leave on the same side of the print they start on.

Source:

http://www.geocities.com/sseagraves/fingerprintingbackground.htm