Editing DNA profiling (section)

==Background==
[[File:Alec Jeffreys -2008.jpg|thumb|Sir [[Alec Jeffreys]], pioneer of DNA profiling. His discovery led to the conviction of [[Colin Pitchfork]] in 1988.<ref name="Eureka"/>]]
Starting in the mid 1970s, scientific advances allowed the use of DNA as a material for the identification of an individual. The first patent covering the direct use of DNA variation for forensics ([https://docs.google.com/viewer?url=patentimages.storage.googleapis.com/pdfs/US5593832.pdf US5593832A]<ref>{{Cite web |title=Espacenet - Bibliographic data |url=https://worldwide.espacenet.com/publicationDetails/biblio?CC=US&NR=5593832&KC=&FT=E&locale=en_EP |access-date=2022-08-22 |website=worldwide.espacenet.com}}</ref><ref>{{Cite web |title=US5593832.pdf |url=https://docs.google.com/viewer?url=patentimages.storage.googleapis.com/pdfs/US5593832.pdf |access-date=2022-08-22 |website=docs.google.com}}</ref>) was filed by [[Jeffrey Glassberg]] in 1983, based upon work he had done while at [[Rockefeller University]] in the United States in 1981.

[[British people|British]] geneticist Sir [[Alec Jeffreys]] independently developed a process for DNA profiling in 1984 while working in the Department of Genetics at the [[University of Leicester]]. Jeffreys discovered that a DNA examiner could establish patterns in unknown DNA. These patterns were a part of inherited traits that could be used to advance the field of relationship analysis. These discoveries led to the first use of DNA profiling in a criminal case.<ref>{{Cite journal |last=Wickenheiser |first=Ray A. |date=Jul 12, 2019 |title=Forensic genealogy, bioethics and the Golden State Killer case |journal=Forensic Science International. Synergy |volume=1 |pages=114–125 |doi=10.1016/j.fsisyn.2019.07.003 |pmid=32411963 |pmc=7219171 }}</ref><ref name="Tautz2">{{cite journal |author=Tautz D |author-link=Diethard Tautz |year=1989 |title=Hypervariability of simple sequences as a general source for polymorphic DNA markers |url= |journal=Nucleic Acids Research |volume=17 |issue=16 |pages=6463–6471 |doi=10.1093/nar/17.16.6463 |pmc=318341 |pmid=2780284}}</ref><ref>{{cite patent|country=US|number=5766847|title=Process for analyzing length polymorphisms in DNA regions|pubdate=1998-06-16|inventor1-last=Jäckle|inventor2-last=Tautz|inventor1-first=Herbert|inventor2-first=Diethard|assign1=[[Max-Planck-Gesellschaft zur Forderung der Wissenschaften]]}}</ref><ref>{{cite journal |vauthors=Jeffreys AJ |date=November 2013 |title=The man behind the DNA fingerprints: an interview with Professor Sir Alec Jeffreys |journal=Investigative Genetics |volume=4 |issue=1 |pages=21 |doi=10.1186/2041-2223-4-21 |pmc=3831583 |pmid=24245655 |doi-access=free }}</ref>

The process, developed by Jeffreys in conjunction with Peter Gill and Dave Werrett of the [[Forensic Science Service]] (FSS), was first used forensically in the solving of the murder of two teenagers who had been raped and murdered in [[Narborough, Leicestershire]] in 1983 and 1986. In the murder inquiry, led by Detective David Baker, the DNA contained within blood samples obtained voluntarily from around 5,000 local men who willingly assisted [[Leicestershire Police|Leicestershire Constabulary]] with the investigation, resulted in the exoneration of Richard Buckland, an initial suspect who had confessed to one of the crimes, and the subsequent conviction of [[Colin Pitchfork]] on January 2, 1988. Pitchfork, a local bakery employee, had coerced his coworker Ian Kelly to stand in for him when providing a blood sample—Kelly then used a forged passport to impersonate Pitchfork. Another coworker reported the deception to the police. Pitchfork was arrested, and his blood was sent to Jeffreys' lab for processing and profile development. Pitchfork's profile matched that of DNA left by the murderer which confirmed Pitchfork's presence at both crime scenes; he pleaded guilty to both murders.<ref>{{cite book | vauthors = Evans C |title=The Casebook of Forensic Detection: How Science Solved 100 of the World's Most Baffling Crimes |year=2007 |orig-date=1998|publisher=Berkeley Books |location=New York |isbn=978-1440620539 |edition=2nd |page=[https://books.google.com/books?id=adKcM055ERoC&pg=PT86 86]–89}}</ref> After some years, a chemical company named [[Imperial Chemical Industries]] (ICI) introduced the first ever commercially available kit to the world. Despite being a relatively recent field, it had a significant global influence on both criminal justice system and society.<ref>{{Cite web |title=DNA Profiling - an overview {{!}} ScienceDirect Topics |url=https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/dna-profiling |access-date=2023-09-24 |website=www.sciencedirect.com}}</ref>

[[Image:D1S80Demo.png|thumb|Variations of [[VNTR]] allele lengths in 6 individuals]]
Although 99.9% of human DNA sequences are the same in every person, enough of the DNA is different that it is possible to distinguish one individual from another, unless they are [[monozygotic twins|monozygotic (identical) twins]].<ref name="Lander">{{cite web |url=http://www.accessexcellence.org/RC/AB/BA/Use_of_DNA_Identification.php |archive-url=https://web.archive.org/web/20080426014318/http://www.accessexcellence.org/RC/AB/BA/Use_of_DNA_Identification.php |archive-date=2008-04-26 |title=Use of DNA in Identification |publisher=Accessexcellence.org |access-date=2010-04-03 }}</ref> DNA profiling uses repetitive sequences that are highly variable,<ref name="Lander"/> called [[variable number tandem repeat]]s (VNTRs), in particular short tandem repeats (STRs), also known as [[microsatellite]]s, and [[minisatellite]]s. VNTR [[locus (genetics)|loci]] are similar between closely related individuals, but are so variable that unrelated individuals are unlikely to have the same VNTRs.

Before VNTRs and STRs, people like Jeffreys used a process called [[restriction fragment length polymorphism|restriction fragment length polymorphism (RFLP)]]. This process regularly used large portions of DNA to analyze the differences between two DNA samples. RFLP was among the first technologies used in DNA profiling and analysis. However, as technology has evolved, new technologies, like STR, emerged and took the place of older technology like RFLP.<ref>{{Cite journal |last=Marks |first=Kathy |date=June 2009 |title=New DNA Technology for Cold Cases |url=https://www.proquest.com/docview/1074789441 |journal=Law & Order |volume=57 |issue=6 |pages=36–38, 40–41, 43 |id={{ProQuest|1074789441}} |via=Criminal Justice (ProQuest)}}</ref>

The admissibility of DNA evidence in courts was disputed in the United States in the 1980s and 1990s, but has since become more universally accepted due to improved techniques.<ref>{{Cite web |last=Roth |first=Andrea |date=2020 |title=Chapter 13: Admissibility of DNA Evidence in Court |url=https://www.law.berkeley.edu/wp-content/uploads/2022/03/Admissibility_of_DNA_Evidence_in_Court.pdf |access-date=2023-03-25 |website=University of California Berkeley School of Law |quote=The original forms of forensic DNA testing and interpretation used in the 1980s and early 1990s were subject to much criticism during the “DNA Wars,” the history of which has been ably told by others (Kaye, 2010; Lynch et al., 2008; see chapter 1). But these earlier techniques have been replaced in forensic DNA analysis by PCR- based STR discrete- allele typing. Courts now universally accept as generally reliable both the PCR process for amplification of DNA and the STR- based system of identifying and comparing alleles (Kaye, 2010, pp. 190– 191).}}</ref>