Fingerprints

While there is evidence that ancient civilizations were aware of fingerprints, the first systematic use of fingerprint identification in the U.S. was in 1902 in New York City.
The first U.S. criminal conviction using fingerprint evidence took place in 1904 in Chicago in the Thomas Jennings case.
The FBI's Identification Division, established in 1924, became a national repository for fingerprint records.

Fingerprints are the distinctive images created when a finger's ridges and furrows are pressed onto a surface.
These friction ridges, found on the palms, soles, and finger and toe tips of all primates, evolved to enhance grip.
Friction ridges develop in the uterus, starting around the 9th or 10th week of fetal development, and remain unchanged throughout life.

Patent prints are visible without assistance because they are made with a transferable substance (e.g., blood, ink) or pressed into a soft material (e.g., clay).
Plastic prints, a type of patent print, are three-dimensional impressions left in moldable materials.
Latent prints, composed of sweat and oils, are invisible to the naked eye and require visualization techniques.

Latent prints can be found using:
- Alternative Light Sources: Many latent prints become visible under laser or black light.
- Chemicals: Substances like iodine and ninhydrin react with amino acids in sweat, causing a color change.
- Cyanoacrylate Fuming: Superglue fumes bind to proteins in fingerprint ridges, creating a white coating that can be further enhanced with powders or chemicals.
- Powders: Colored, fluorescent, or magnetic powders are brushed lightly over surfaces, creating contrast to reveal the print.

Sir Francis Galton was the first to study fingerprints scientifically and develop a classification system still used today.
Friction ridges are considered unique, with an extremely low probability of two individuals having identical prints.
Fingerprint identification relies on analyzing minutiae, the unique ridge characteristics (e.g., ridge endings, bifurcations) and their arrangement.
The Henry Classification System, developed in the early 1900s, categorizes fingerprints based on pattern types (loops, arches, and whorls) for efficient database searching.
Modern fingerprint identification relies on comparing minutiae and higher-level details.
Automated Fingerprint Identification Systems (AFIS) are computerized databases used to store, search, and retrieve fingerprints.

While some attempts have been made to alter fingerprints, these modifications often make the prints easier to identify due to added scars and damage.

Level 1 - ridge pattern

Level 2 - formation of the ridge

Level 3 - details within the ridge