DNA as a crime-fighting tool under review

It contains every single detail about you, from the colour of your eyes to your likelihood of developing a life-threatening disease, and you leave it everywhere you go. On discarded coffee cups and half-eaten museli bars that have been carelessly tossed into rubbish bins. It is DNA, and if you’re a suspect in a crime – or a family member is suspect – then it may become of great interest to the police.

How that sample is obtained, what it is used for, whether it is discarded – all of that is governed by the Criminal Investigations (Bodily Samples) Act 1995 (CIBS Act). The legislation was amended in 2003 and 2009, but a review by the Law Commissions concludes that the its time for an entirely new Act, one that will take into the account the developments in science as well as human rights issues, Treaty of Waitangi ethical and tikanga issues, and privacy issues. The Commission began its investigation into the CIBS Act in July 2016 and released a 367-page issues paper shortly before Christmas.

While the Minister of Justice is responsible for the CIBS Act, the reality is that it is the police and ESR (the Crown Research Institute that provides the forensic services) that administer the Act. They effectively have two databanks – the Crime Sample Databank (DNA profiles taken from samples lifted from crime scenes, for example blood on a victim’s shirt etc), and a Known Person Databank (DNA profiles from samples from convicted criminals and others who have provided samples through consent).

As police use DNA to link people to crime scenes, it can be a powerful investigative tool. The technique has been used to help solve crimes such as the murder of Teresa Cormack – 14 years after the investigation into her death began. The breakthrough in the case was when scientists were able to find a usable DNA sample in 2001, and it was compared to 800 reference samples that were obtained from people who had been nominated as suspects during the investigation, leading to the identification – and subsequent conviction – of Jules Mikus.

High profile cases, and the influence of US TV dramas, have led people to believe that DNA profiling is used widely, whereas in reality the Commission estimates it is used in only 0.5 – 2% of all criminal investigations in New Zealand.

While the actual use of DNA might be relatively small, what it can tell about a person – and their family – is huge, as the Commission notes: “The sampling process… results in the State taking possession of (and therefore seizing) a biological sample that contains the entire genetic blueprint of the individual. This includes information about the person’s health, ethnicity and family relationships”.

So, what are the rules around gathering these samples? The Commission’s paper looks into how consent is applied and how this may be adversely affected by the power imbalance and it discusses how Māori may be unfairly targeted in the process of DNA collection. It also points out that it is possible for police to obtain a DNA sample indirectly – that is by watching a person throw a drink bottle into a public rubbish bin and then collecting it later to obtain the saliva.

The Commission suggest new legislation needs to consider how DNA samples are obtained. It draws an analogy with searches of electronic devices in which the Supreme Court has held that because people are not always aware of the extent of the information contained on their device unique privacy interests are engaged, and special search and surveillance rules should apply. The counter to this argument is the administrative burden this could place on police and if it would potentially impede the investigation of an horrific crime.

Then there are practices such as DNA phenotyping, where scientists are able to extract information about a person’s physical characteristics from a DNA sample left at a crime scene. This raises significant ethical and legal issues. The Law Commission argues that DNA phenotyping is not in keeping with the original public mandate for the CIBS Act and this should be something that Parliament needs to consider as part of the process of creating a new act governing the use of DNA as a crime-fighting tool.

Another decision for Parliament is whether New Zealand should opt for a universal DNA profile databank. Kuwait tried to establish one in 2015, but it was ruled unconstitutional in 2017, as it violated personal liberty. Portugal also tried to establish a universal DNA database, but public pressure meant the government had to limit it to criminal offenders.

If we don’t enact a universal database then there should be rules in place governing whose DNA profiles are held by the State, and why, as the Commission notes: “When considering consistency, there is also a particular need to ensure that the statutory framework is consistent with the Treaty of Waitangi principles of equity and partnership. The collection and retention of DNA samples and profiles has a disproportionate impact on Māori… the data shows that Māori are already disproportionately represented on the DPD (DNA Profile Databank). This is particularly the case for rangatahi Māori.”

DNA is powerful, and the State has a duty of care to protect the privacy of its citizens. The Commission is recommending that as part of the reform CIBS Act, a public agency be established to provide independent oversight of how the police and ESR use DNA in criminal investigations. Having read the full paper, it strikes me as an idea that is well overdue.

The issues paper can be found here. Submissions close 31 March 2019.


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