Author Mark Twain put fingerprint evidence into some of the books he wrote. In Life on the Mississippi, a murderer is identified by the use of fingerprint identification. And Pudd’n Head Wilson, another of Twain’s books, includes a dramatic court trail featuring fingerprint evidence.
Although identical twins share the same DNA, they do not share identical fingerprints. No two individuals have the exact same fingerprints.
Burns and scrapes will not change fingerprints. When new skin grows, the same pattern comes back.
It takes approximately 12 hours for food to entirely digest. This information can help determine a person’s time of death.
Like fingerprints, tongue prints are unique to each person. No two people have identical tongue prints.
A human being loses an average of 40 to 100 strands of hair a day. Criminals don’t realize they probably are leaving hair evidence at the crime scene.

  • Fingerprint
  • What Type of Fingerprints
    Do You Have?
  • How To Take Your
    Own Fingerprints
Ancient Times
Ancient Babylonians used fingerprints on clay tablets for business contracts. Thumb prints have been found on ancient Chinese clay seals.

Sir William Herschel of England used fingerprints on contracts with natives in India. He believed that no two people shared the same fingerprints.

Dr. Henry Faulds, an Englishman working in Japan, came up with a method to classify fingerprints. He also was one of the first to use printer ink to get fingerprint samples.

Francis Rojas was the first person convicted of murder based on fingerprint evidence. This woman murdered her two sons and then cut her own throat. She tried to place blame on someone else. But her bloody fingerprint on the doorpost proved her guilt.

The New York State Prison system began using fingerprints to identify U. S. criminals.

The Federal Penitentiary in Leavenworth, Kansas, began using fingerprints to identify prisoners.

U.S. Army began using fingerprints.

U.S. Navy began using fingerprints.

U.S. Marine Corps began using fingerprints.

The U. S. Congress established the Identification Division of the FBI began. This group was responsible for forming the FBI fingerprint files.

The Department of Homeland Security began overseeing the Automated Fingerprint Identification System (AFIS) containing the fingerprints of more than 74 million people
Arch Pattern—
ridges enter from one side, rise slightly in the center and go back down again (a little like a hill)
Loop Pattern—
ridges enter from either side, curve up and down in steep loops
Whorl Pattern—
ridges are circular and look a little like age rings on a tree trunk
What You Need
plain paper
plain 3-x5-inch index cards
transparent tape
marking pen
wet washcloth
What You Do
1.  Rub the pencil on the paper to make a small dark rectangle.
2.  Press and rub one of your fingers in the pencil-darkened rectangle.
3.  Place a piece of transparent tape on your darkened finger.
4.  Carefully peel off the tape and attach it to the index card.
5.  Clean your fingertip with the wet washcloth to prevent unwanted smudges or extra fingerprints.
6.  Use the marking pen to label your name and the fingerprint (for example: right hand, index finger). You should be able to get prints for four fingers and one thumb on a single index card.
7.  Continue steps 1 – 6 until you have all ten fingerprints.
Q.  What is a CSI?
A.  Crime Scene Investigator documents, identifies, and collects physical evidence at a crime scene.

What are ETs, CSTs, and CSAs?


The job of Crime Scene Investigator (CSI) has many names. A CSI might also be called an Evidence Technician (ET), a Crime Scene Technician (CST), or a Crime Scene Analyst (CSA). The names are different, but the job is pretty much the same.

Q.  What education do I need to become a CSI?

Different law enforcement agencies have different educational requirements. Beyond high school, you will most likely need a two-year (associate) or a four-year (bachelor) college degree.


What college courses should I take to become a CSI?


Degrees in biology, chemistry, or forensic science would be good choices for anyone interested in crime scene investigation. A degree in law enforcement is another good choice. Many CSIs became police officers first and later became CSIs when the positions became available.


Where do I get training to become a CSI?


Training is usually offered by the agency that hires you. First you need the education to get hired. Training will follow once you are on the job.