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Organisations such as Ancestry DNA and 23andMe offer at-home DNA testing services to allow people to discover their family heritage and connect with distant relatives. Your very own episode of Where Are You Really From. What’s not to like about that?

But there is a downside: handing over your DNA potentially erodes the rights of people accused of serious crimes. Familial DNA opens up new frontiers in the search for alleged criminals. But they are a back door way to justice which contravene established practices. 

Familial DNA searching has been used extensively for many years throughout the United Kingdom and has led to many criminal convictions. The United States has also successfully used this technique to solve many cold cases, including the identification of the infamous “BTK Killer” and the Golden State Killer.  

In the last few years, familial DNA testing has led to a number of breakthroughs for police in Australia. South Australian police identified the North Adelaide rapist after years of no leads, and in Queensland the murder of a woman from Cooktown was solved using this technique.  

So how does catching criminals relate to genealogy companies?

Well, people who have provided their DNA to genealogy websites, such as Ancestry DNA and 23andMe are unaware that this data can be potentially used in a criminal investigation.

This means an individual can submit their own DNA and, consequently, shared biological characteristics of their family members (even those very distantly related) can be identified. 

Public databases such as GEDmatch are designed for comparison of DNA profiles from testing companies such as Ancestry.com. It is essentially a centralised pool of sensitive biological information, accessible at the click of a button. This opens up a new world of potential for law enforcement agencies.

The Golden State Killer’s DNA profile was found using GEDmatch, without a court order or compulsion by law. This case example, and others globally, invoke important questions about what safeguards are needed to combat potential erosion of the rights of an accused person.

There are also concerns surrounding the ability of the state to conduct genetic surveillance of people through enhanced access to a gamut of biological information. 

Familial DNA searching

It is easy to see why familial DNA searching has gained considerable traction and support for its crime-solving potential. 

This particular forensic technique allows identification of biological relatives to an unknown DNA profile. This can be compared to traditional DNA testing (that relies on an exact match of DNA material to a known DNA profile) which has been regarded as critical tool in criminal investigation since its introduction in the 1980s.

The benefit of familial testing over traditional DNA analysis is that it extends the search capabilities considerably. Interestingly, associate professor of pathology Fredrick Bieber and colleagues state that the use of familial searching could yield positive match results at an increase of around 40%.

The law

The taking of DNA samples from a suspect in a criminal investigation is governed by various legislation in Australia. In New South Wales, the Crimes (Forensic Procedures) Act 2000 regulates such forensic procedures.

The taking of blood, saliva or the swabbing of a person’s body for the purpose of obtaining biological material, is considered an “intimate” forensic procedure. Any procedure must be obtained with informed consent of the accused person, otherwise alternate legal authorisation is required. 

A significant part of the informed consent is permitting the suspect to communicate privately with a legal practitioner.

In a system underpinned by procedural fairness, it is vital that people are given the option to communicate with a lawyer who can explain the various implications of either supplying or not supplying a DNA sample. It is equally as important that an accused play an active and informed role in any procedures or processes related to a crime they are alleged to have committed.

The unintended consequences

While Ancestry DNA and 23andMe do not typically operate the same as more public resources like GEDmatch, there is still scope for them to be similarly used in criminal investigations.

Both Ancestry DNA and 23andMe claim that while they do not “voluntarily” share personal information with law enforcement agencies, they are subject to compulsion by the law. This means that if they are subpoenaed or issued with a court order, they must hand over genetic material in their possession. Equally troubling is the fact that most of these companies retain the biological sample indefinitely unless given express instructions to destroy it.

This is particularly problematic given that there is potential to circumvent the need for the accused’s knowledge or involvement in this process, which is enshrined in law.  

The Crimes (Forensic Procedures) Act 2000 has robust safeguards for an accused, for very good reason. An accused is provided a detailed statement about the collection and what the sample will be used for, including what the profile will be tested against to ensure an informed choice is made.

Therefore, using genealogy company’s data to match an unknown profile means the accused is entirely unaware of the process. This has the potential to undermine the due process rights and public confidence in our system of justice.   

Rhanee Rego is a solicitor, casual academic and PhD candidate at the Newcastle Law School, University of Newcastle, NSW. She practises predominantly in criminal law and her main research interests are in miscarriages of justice and post-conviction review. 

John Anderson is professor of law at the Newcastle Law School, University of Newcastle, NSW and has a national and international profile as a criminal law and evidence scholar.