Have you ever submitted a DNA sample to map your family tree? The rising popularity of genealogy websites and companies like Ancestry.com, 23andMe and GEDmatch have seen many people submit a swab of their saliva for DNA identification and mapping. Though it may be interesting to discover your ancestry or long-lost relatives, there is a possibility that your sample may be used in the investigation of criminal offences.


Online service identifies Golden State Killer

In 2018, US police used samples provided to GEDmatch, an online service that collates DNA data from other testing companies, to identify a suspect alleged to be the infamous Golden State Killer, thought to have committed at least 13 murders, 50 rapes, and 100 burglaries in California from 1974 to 1986.

Joseph James DeAngelo was identified as a suspect after police matched a decade old DNA sample from a crime scene with DNA material provided to the online service by De Angelo’s distant relatives. DeAngelo was committed to trial last week.

Australians are among the most common users of GEDmatch, the service used to identify DeAngelo. This raises the question of whether cold cases in Australia may be solved in a similar manner.


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Currently, DNA testing and other forensic procedures in NSW are regulated by the Crimes (Forensic Procedures) Act 2000 (NSW). The material is stored on two national databases. DNA information currently used in Australian criminal law is more limited than that held by online ancestry services, which are said to contain 35,000 more sites of your DNA than traditional police tests yield. Accordingly, while information held by police may allow them to identify suspects through comparison with their close relatives (such as a parent or sibling), commercial testing can identify offenders through extended family. In the case of the Golden State Killer, DeAngelo was tracked down through the DNA profiles of his third and fourth cousins.

Who may have their DNA collected by the police?

Another difference lies in the material that is allowed to be entered into and stored on these databases. In NSW, only specific people are to have their DNA entered into the national database. This includes:

  • Suspects of a crime,
  • Anyone serving a sentence of imprisonment for a serious offence,
  • Former offenders, who have served a sentence of imprisonment for a serious offence, and whose DNA is not contained on the national database,
  • Registrable persons under the Child Protection (Offenders Registration) Act 2000.

The forensic material can only be obtained with the informed consent of the person, or by a court order. If a person is not convicted, or if they are convicted but the conviction is later set aside or quashed, the forensic material must be destroyed. If no proceedings are taken against a suspect who provided a sample, or proceedings are discontinued, the material must be destroyed within 12 months.

In contrast, anyone can freely give their DNA information to online commercial services. In doing so, people may unwittingly expose themselves or their relatives to a criminal investigation.

However, research has found that many people are supportive of providing their genetic material to aid in criminal investigations, even if it may lead to the conviction of a family member.

How is the use of DNA regulated?

The use of information held by these online databases is mostly regulated by the companies themselves, and their policies outlining how the information is to be used. Because GEDmatch is available for anyone to search, the police involved in identifying the Golden State Killer suspect did not even require a warrant to access the information. When logging into the site, users are warned that their information may be searched by law enforcement agencies to identify familial matches in the investigation of crimes. Similarly, users of Ancestry.com may too have their DNA information used in criminal investigations,

Whose DNA is it?

Another issue lies in the information provided to these online services. Because providing information to sites like 23andMe is on a voluntary basis and there is no way to monitor whether people are providing truthful and accurate registration information, the site cannot verify a person’s identity. For this reason, 23andMe recognises that it does not have the means to “reliably connect any particular DNA sample or account to an individual”. This may provide another challenge to the use of such information by law enforcement. Even if a DNA sample is matched, there is no guarantee that the identity of the person attached to that sample is the person from whom the DNA was obtained.

Key Takeaways

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If you have been charged with an offence, you can contact the team at Hamilton Janke Lawyers 24/7 by calling 4038 1666.

Written By
Picture of James Janke
James Janke

James Janke is founding partner at Hamilton Janke Lawyers, and has more then decade of experience as a Criminal Defence Lawyer. Admitted to both the Supreme Court of New South Wales and High Court of Australia