A fingerprint is an impression left by the friction ridges of a human finger. The recovery of partial fingerprints from a crime scene is an important method of forensic science. Moisture and grease on a finger result in fingerprints on surfaces such as glass or metal. Deliberate impressions of entire fingerprints can be obtained by ink or other substances transferred from the peaks of friction ridges on the skin to a smooth surface such as paper. Fingerprint records normally contain impressions from the pad on the last joint of fingers and thumbs, though fingerprint cards also typically record portions of lower joint areas of the fingers.
A fingerprint
The friction ridges on a finger
A non-tented fingerprint arch
A fingerprint loop
Forensic science, also known as criminalistics, is the application of science principles and methods to support legal decision-making in matters of criminal and civil law.
Ambroise Paré's surgical work laid the groundwork for the development of forensic techniques in the following centuries.
This is an example and explanation of extractor/ejector marks on casings.
Apparatus for the arsenic test, devised by James Marsh
Fingerprints taken by William Herschel 1859/60