Forensic DNA

For details of laboratories for forensic DNA analsys see the list of forensic and ancient DNA laboratories

For a good introduction to the use of DNA in criminal investigations read the guide from Sense About Science on Making Sense of Forensic Genetics.

Forensic STR analysis

Short tandem repeat (STR) analysis is a relatively new technology in the field of forensics, having come into popularity in the mid-to-late 1990s. It is used for the genetic fingerprinting of individuals. STRs are extracted from autosomal DNA, DNA which is inherited from both parents. Autosomal STRs can, therefore, be used to identify both males and females.

In the United States, 13 core autosomal STR loci (markers) have been selected as the basis by which an individual genetic profile can be generated. These profiles are stored at a local, state and national level in DNA databanks such as CODIS. The United Kingdom database for STR loci identification is the UK National DNA Database (NDNAD). In Europe the DNA-17 test is used. This test uses 16 autosomal STRs and a gender marker. The UK National DNA Database was upgraded with effect from July 2014 to take account of the new test.

Note that the DNA tests used in surname DNA projects look at Y-chromosome STRs (Y-STRs). The autosomal STRs used for forensic analysis identify one person in a million. In contrast Y-STR signatures are shared by many people with the same surname and do not identify an individual. The autosomal DNA tests used by genetic genealogists look at autosomal SNPs (single nucleotide polymorphisms and not autosomal STRs.

Forensic DNA databases

• Canada's national DNA databank
• CODIS - the FBI's Combined DNA database system
• The UK National DNA database – the website includes some useful explanations of the type of testing used
• DNA Policy Initiative Wiki This Wiki maintains listings of forensic DNA databases around the world and links to related articles

Scientific papers

• Parson W, Huber G, Moreno et al (2015). Massively parallel sequencing of complete mitochondrial genomes from hair shaft samples. Forensic Science International: Genetics 15: 8–15.
• Maguire CN, McCallum LA, Storey C, Whitaker JP (2014). Familial searching: a specialist forensic DNA profiling service utilising the National DNA Database to identify unknown offenders via their relatives – the UK experience. Forensic Science International: Genetics 8: 1-9.
• Rohlfs RV, Murphy E, Song YS, Slatkin M (2013). The Influence of Relatives on the Efficiency and Error Rate of Familial Searching. PLoS ONE 2013 8(8).
  • See also: Our paper: The influence of relatives on the efficiency and error rate of familial searching Rohlfs R. Haldane's Sieve blog, 19 April 2013.
• Mark W Perlin (2013). When good DNA goes bad. Journal of Forensic Research 2013, S11.
• Douglas R Hares (2012). Expanding the CODIS core loci in the United States Forensic Science International: Genetics Volume 6, Issue 1, January 2012, Pages e52–e54.
• Kim J, Mammo D, Siegel MB. & Katsanis SH (2011). Policy implications for familial searching. Investigative Genetics 2: 22 .
• Krane, DE and Bahn, V and Balding, D et al (2009). Time for DNA disclosure (letter). Science 326 (5960) 1631-1632.
• Budowle, B, Shea B, Niezgoda S, Chakraborty R (2001). CODIS STR Loci Data from 41 sample populations. Journal of Forensic Sciences 46(3):453-489.

News stories

• Killer breakthrough – the day DNA evidence first nailed a murderer by Ian Cobain. The Guardian, 7 June 2016.
• The dark side of DNA databases by Erin E Murphy. The Atlantic , 8 October 2015.
• FBI notifies crime labs of errors used in DNA match calculations since 1999 by Spencer S Hsu, Washington Post, 29 May 2015.
• FBI audit of database that indexes DNA finds errors in profiles by Joseph Goldstein, New York Times, 24 January 2014.
• The US is building massive DNA database by Erin Murphy. Scientific American, 1 March 2013.
• Unreliable evidence. Time to open up DNA databases? by Linda Geddes. New Scientist, 6 January 2010.
• Courtroom Science Drama: The Saga of Amanda Knox’s DNA by Ars Technica. Wired magazine, 10 December 2012.
• Travis J. Scientists Decry "Flawed" and "Horrifying" Nationality Tests Science Insider, 29 September 2009.
• Balding D, Weale M, Richards M, Thomas M Genetic and isotope analysis and the UK Border Agency. Significance June 2010, pp58-61.
• Tremlett G. Tracing Adam. The Guardian, 7 August 2003.

Blog posts

• The great paternal DNA quest An article about extracting DNA from hospital biopsy samples for the author's parents. 12 February 2017.
• DNA and the locks of hair by Judy Russell, The Legal Genealogist, 3 June 2012
• Digging Up Dad, Exhumation and Forensic Testing Alternatives by Roberta Estes, DNAeXplained, 30 April 2013.

Useful links

• Primer: Forensic DNA Analysis A free download from the Royal Society (UK)
• The reality of DNA phenotyping By Greg Emmerich, Promega Connections 18 May 2016
• Challenges in DNA Testing and Forensic Analysis of Hair Samples by Caroline Hughes, Forensic Magazine 4 February 2013.
• DNA evidence basics An easy-to-understand introduction to forensic DNA from the US National Institute of Justice
• Wikipedia article on DNA profiling
• DNA Forensics a collection of articles from the Human Genome Project Information
• DNA guidance A collection of articles published by the UK'S Forensic Science Regulator
• Scientific Working Group on DNA Analysis Methods
• DNA View Charles Brenner's Forensic Mathematics website
• Report to the President. Forensic Science in Criminal Courts: Ensuring Scientific Validity of Feature-Comparison Methods A report compiled by the Executive Office of the President, President’s Council of Advisors on Science and Technology September 2016.
• DNA and biological evidence Resources from NIST (the US National Institute for Science and Technology)

Organisations

• Euroforgen - the European Forensic Genetics Network of Excellence for forensic genetic research. See in particular the ist of consortium publications and the collection of videos explaining forensic genetics

See also

• List of forensic and ancient DNA laboratories
• Ancient DNA