The Forensic Science and History of Fingerprints

Gold Standard: For nearly a century ( $100$ years), fingerprints have served as the "gold standard" of forensic science.
Biological Persistence: The fingerprint pattern is one of the earliest features to develop in the womb. Once formed, the shape stays the same from "cradle to grave."
Consistency: While the physical pattern of hills and valleys grows larger as the human body grows, the actual shape remains constant throughout the individual's life.

Formation Timeline: Fingerprints "lock in" at approximately the $24^{th}$ week of development.
Deterministic Factors: The formation of unique patterns is influenced by multiple factors during gestation: - The pressure of amniotic fluid across the surface of the developing hands. - The specific growth rate of the fingers.
Uniqueness: Because of the high number of factors in play, every person's prints are unique; this includes identical twins, who do not share fingerprint patterns despite sharing identical DNA.

Functional Utility: The actual evolutionary purpose of fingerprints is more basic than identification; they exist to help humans grab and pick up objects.
Mechanotransduction: The function they serve is specifically so we can pick up things effectively.
Friction Ridges: The three-dimensional ridges create friction, which enables easy grasping of objects.
Lasting Impressions: Because these ridges are three-dimensional and "bumpy," they leave a lasting impression whenever they make contact with a surface.

Ancient China (Year February): As early as the year February, the ancient Chinese utilized fingerprints to sign legal documents. However, at this time, they did not realize just how individual and unique these marks truly were.
Scientific Breakthrough Lag: It would be more than a thousand ( $1000$ ) years before the scientific understanding of fingerprint individuality was established.
$1684$ : The English physician Nehemiah Grew published the first documented scientific analysis of the ridges found on the fingers and palms.
$1788$ : Approximately $100$ years after Grew, the German anatomist Johann Meyer advanced the science by declaring that no two people share the same fingerprints.
Late $19^{th}$ Century: This era marked the first time the science of fingerprints played a central role in a criminal investigation.