fingerprints.
The police have many ways of catching. One way of catching them is to identify them by fingerprinting. Fingerprinting is the study of the patterns on our fingertips. We have know that no two fingerprints are exactly the same for hundreds of years. However it wasn't until 1910, in Chicago, that the first criminal in the USA was convicted using fingerprint evidence.
Early on the morning of 19 September 1910, Clarence Hiller is wife noticed that a light which they usually left on was off. When Clarence went to investigate, he came across a stranger at the top of the stairs. The stranger had broken in and was about to burgle the house. Hiller and the stranger started to fight, but the stranger had a gun.He shot Hiller twice and ran away. Hiller is wife ran to him when she heard the gunshots but found him dead. Soon after, the police arrested a man named Thomas Jennings not far from the Hillers' house.
The only problem was that there were no witnesses to the murder. However the police had recently started using fingerprinting in criminal cases. Only hours before his death,Hiller had painted some wood near his kitchen window. The police found some fingerprints in the wet print. During the trial, the police proved that the fingerprints belonged to Jennings, and he was convicted of Hiller is murder. Since then, fingerprinting has helped in the conviction of hundreds of thousands of criminals.