Editing Fingerprint (section)

== {{anchor|Dactyloscopy}}Fingerprint identification ==
Fingerprint identification, known as '''dactyloscopy''',<ref name=ashbaugh1>{{cite web|url=http://onin.com/fp/ridgeology.pdf|title=Ridgeology - Modern Evaluative Friction Ridge Identification |last=Ashbaugh|first=David R.|access-date=October 26, 2013|publisher=Royal Canadian Mounted Police|url-status=live|archive-url=https://web.archive.org/web/20130523072315/http://onin.com/fp/ridgeology.pdf|archive-date=May 23, 2013}}</ref> ridgeology,<ref>{{Cite journal |last=Ashbaugh |first=David |date=1991 |title=Ridgeology |url=https://chance.dartmouth.edu/chance_news/for_chance_news/ChanceNews12.05/ridgeology.pdf |journal=Journal of Forensic Identification |volume=41 |issue=1 |pages=16–64}}</ref> or hand print identification, is the process of comparing two instances of friction ridge skin impressions (see [[minutiae]]), from human fingers or toes, or even the palm of the hand or sole of the foot, to determine whether these impressions could have come from the same individual. The flexibility and the randomized formation of the friction ridges on skin means that no two finger or palm prints are ever exactly alike in every detail; even two impressions recorded immediately after each other from the same hand may be slightly different.<ref name= ashbaugh1 /> Fingerprint identification, also referred to as individualization, involves an expert, or an [[expert system|expert computer system]] operating under [[Adaptive thresholding|threshold scoring]] rules, determining whether two friction ridge impressions are likely to have originated from the same finger or palm (or toe or sole).

In 2024, research using [[Deep learning|deep learning neural networks]] found contrary to "prevailing assumptions" that fingerprints from different fingers of the same person could be identified as belonging to that individual with 99.99% confidence. Further, features used in traditional methods were nonpredictive in such identification while ridge orientation, particularly near the center of the fingerprint center provided most information.<ref name="Guo Ray Izydorczak Goldfeder 2024 p.">{{cite journal |last1=Guo |first1=Gabe |last2=Ray |first2=Aniv |last3=Izydorczak |first3=Miles |last4=Goldfeder |first4=Judah |last5=Lipson |first5=Hod |last6=Xu |first6=Wenyao |date=2024 |title=Unveiling intra-person fingerprint similarity via deep contrastive learning |journal=Science Advances |volume=10 |issue=2 |pages=eadi0329 |doi=10.1126/sciadv.adi0329 |issn=2375-2548 |pmc=10786417 |pmid=38215200|bibcode=2024SciA...10I.329G }}</ref> 

An intentional recording of friction ridges is usually made with black printer's [[ink]] rolled across a contrasting white background, typically a white card. Friction ridges can also be recorded digitally, usually on a glass plate, using a technique called [[live scan]]. A "latent print" is the chance recording of friction ridges deposited on the surface of an object or a wall. Latent prints are invisible to the naked eye, whereas "patent prints" or "plastic prints" are viewable with the unaided eye. Latent prints are often fragmentary and require the use of chemical methods, [[fingerprint powder|powder]], or alternative light sources in order to be made clear. Sometimes an ordinary bright flashlight will make a latent print visible.

When friction ridges come into contact with a surface that will take a print, material that is on the friction ridges such as [[perspiration]], oil, grease, ink, or blood, will be transferred to the surface. Factors which affect the quality of friction ridge impressions are numerous. Pliability of the skin, deposition pressure, slippage, the material from which the surface is made, the roughness of the surface, and the substance deposited are just some of the various factors which can cause a latent print to appear differently from any known recording of the same friction ridges. Indeed, the conditions surrounding every instance of friction ridge deposition are unique and never duplicated. For these reasons, fingerprint examiners are required to undergo extensive training. The scientific study of fingerprints is called [[dermatoglyphics]] or dactylography.<ref>“Dactylography.” Merriam-Webster.com Medical Dictionary, Merriam-Webster, https://www.merriam-webster.com/medical/dactylography. Accessed 22 Nov. 2024.</ref>