For more than a century, fingerprints, palm prints and sole prints have been used as identification tools by law enforcement. Collectively known as "friction ridge analysis," this forensic method involves examiners comparing the details of an unknown print with a set or a database of known prints. These details include ridges, loops, whorls and other points of similarities.
According to the National Academies of Sciences, no peer reviewed scientific studies have ever been done to prove the basic assumption that every person's fingerprint is unique. Recent studies have also shown that fingerprint examiners can be influenced by contextual bias when comparing fingerprints.