Law Commission puts DNA rules under microscope

A tactic used to track down and arrest a United States man accused of being a notorious serial killer will be part of a review into how DNA is used to solve crimes in New Zealand.

In April this year, Joseph James DeAngelo was charged over a string of killings around California four decades ago, attributed to the ‘‘Golden State Killer’’. Law enforcement authorities said they were able to link DeAngelo as a suspect by using a genealogy service.

The genetic profile of one of DeAngelo’s distant relatives, which had been loaded on to a genealogical site, was compared by investigators with DNA found at the crime scenes.

This helped narrow the search and, along with other evidence, led them to DeAngelo. He was then followed by officers, who picked up an item he discarded.

This was tested and resulted in a DNA match between the accused and the crime scenes.

However, similar headlines involving high profile New Zealand cold cases are unlikely for now as police have categorically ruled out this ploy of turning to paid genealogical websites.

‘‘Police has not and is not considering the use of genetic information contained on consumer genealogical websites,’’ a spokesperson said in a written statement to Stuff.

The use of DNA by police is enshrined in the 1995 Criminal Investigations (Bodily Samples) Act 1995, a law which is currently under review.

Undertaken by the Law Commission, the re-assessment will consider whether the law is keeping pace with developments in forensic science, international best practice and public attitudes.

Despite the current police stance on the issue, law commissioner Donna Buckingham confirmed the question of familial searching and the use of genealogical websites to identify possible suspects would form part of its re-think, with an issues paper due to be released on October 8.

Familial searching of the police DNA database, which is managed by the Institute of Environmental Science and Research (ESR) already takes place but under strict controls.

There are effectively two databases in New Zealand which hold DNA. One stores the genetic information of about 185,000 people charged with, or convicted of, certain crimes or who had voluntarily provided a sample. The other database stores unknown DNA found at crime scenes.

A protocol between police and ESR allows for familial searches, where the database can be searched for close matches to an unknown DNA sample.

However, this is only carried out in serious cases, where there is no other evidence and when the proper authorisation has been given.