What are forensic 'individualistic characteristics' of evidence?

What are forensic 'individualistic characteristics' of evidence?

Richard Saferstein (Former Chief Forensic Scientist) gives expert video advice on: What is forensic science?; What is forensic 'physical evidence'?; What is forensic 'identification' of physical evidence? and more...

Let me give you two examples. The first is the fingerprint. There are what we call minutiae or fingerprint ridge characteristics that a fingerprint specialist will look for and will match up between two fingerprints that are being compared. If the position and the type of ridge characteristics are identical and there are enough of them, the fingerprint specialist can then come to a conclusion that the two fingerprints came from the same individual. The other area that I would like to refer to would be DNA typing. We look for certain DNA types when we collectively examine an item of physical evidence for its' DNA character and, if there are enough of these different types of DNA that exist, we can then make the determination that the DNA emanated from only one individual.