There are forensic scientists discovering and applying new scientific techniques to help solve cases and uncovering clues in cold cases.  Since fingerprints are the most fragile pieces of evidence in a criminal investigation and are the most important to identify the perpetrator, they are the first to be located, documented, retrieved, and examined.

Some of the most common ways to retrieve a fingerprint at a crime scene is by dusting techniques, cyanoacrylate fuming (Super glue), and using various/alternate light sources.  Other applications used are the Magana brush, nindydrin, silver nitrate, and amino black.

During my internship at a police forensic lab in the fingerprint section, I used the ninhydrin method (reacts with the amino acids in fingerprints) and sprayed a letter document in question to develop a print.  I felt a little bit like Sherlock Holmes waiting for the print to appear.  The readable print turned purple/pink in color.  Then…