Posts Tagged ‘DNA’

“The role of DNA evidence in the Criminal Law” was the subject of today’s talk by Dr Debra Wilson. Debra specialises in criminal and medical law and is a passionate researcher and campaigner around the issue of surrogacy.

It was in 1986 that DNA was first used in criminal investigation in the U.K., where it resulted in a murderer being found and a previous suspect being exonerated. By 1995 the U.K. had a DNA data bank, and Aotearoa followed in 1996. Our law has not changed since that time, but the science has evolved, and the N.Z. Law Commission has been looking at what our law could be.

Matching DNAs can prove the likelihood of someone being the offender sought, e.g. that the chance of a match is 5 out of 10,000. Despite what we see in television programmes such as CSI, DNA is found in less than 1% of crime scenes, and it is not always 100% reliable. Debra mentioned the Phantom of Heilbronn, where the DNA of a specific woman turned up in multiple crime scenes in Europe between 1993 and 2009. It was later discovered that the source of the DNA was a cleaner who had contaminated the swabs with which the DNA was taken.

Our Law Commission reported in 2020 that the collection and use of DNA in crime investigations will always require the consideration of the clash of two rights or competing interests. These are:

  • The right of society to be free from crime and/or to have crimes investigated and the criminals punished
  • The right of people to genetic privacy

One form of DNA use is Familial Testing which can identify family members of the offender. Some issues with this are:

  • False positives
  • Invasion of privacy of those on the data bank
  • Invasion of privacy of family members of those on the data bank

In the U.K. anyone who is arrested has their DNA added to the data bank. In Aotearoa our current legislation does not specifically consider or permit familial testing. Half of the people on the N.Z. data bank gave samples voluntarily (e.g. to be excluded from a particular investigation) and did not consent to their wider use. The Law Commission has suggested that any familial testing should be heavily regulated, requiring something similar to a search warrant.

Another form of DNA use is Phenotyping, where DNA can be used to draw a picture of the suspect. Currently DNA can provide a person’s sex, race, eye and hair colour, and age. (As we age our chromosomes get shorter which means our age can be identified within five years.) In future it’s possible that DNA could show our dominant hand, height, and build, maybe even our medical condition and behaviour. Some of the issues with phenotyping are:

  • Most physical traits do not stem from one particular gene
  • Results may not always provide useful information
  • There are racial implications
  • Results may be affected by environmental factors, e.g. height is genetic, but diet is also an important factor

Phenotyping is illegal in Aotearoa, but Debra said it has been used at least eleven times since 2007.

So, where should the line be drawn between catching criminals, and respecting people’s genetic privacy? Younger people, who are used to sharing personal information on social media, are much less likely to care about genetic privacy than their elders. Debra suggested we see DNA as being owned by the entire family, as any analysis may apply to siblings and parents as well as the person being tested. For instance we may not want to know if there is genetic alcoholism in our family, especially as there may be an obligation to disclose such information to an insurer or a prospective employer. When asked about the use of information from Ancestry.com DNA database she said it has been used many times, which appeared to contradict the information given by genealogist Fiona Brooker the previous week . However we were assured that local genealogy databases cannot give DNA information to the police.

We need to consider how we can safely use genetic information without enabling the possibility of eugenics. There are ethical concerns over the possibility of dragnet testing where whole communities are asked to supply DNA samples. If this happens and people refuse, they may be put under pressure, and stigmatised. If the Government asked for everyone to supply a DNA sample, e.g. for Covid testing, how many of us would comply without question?

If you have ever been arrested
your DNA may have been tested

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