DNA use in Law Enforcement
The use of DNA with lesser offences is contentious and contested. But there might be more public support out there than sometimes imagined.
As a widely reported case has shown, until recently the San Fransisco authorities retained for years the DNA data of women who have gone through the ‘rape kit’ process following a sexual assault, or alleged sexual assault, upon them. These samples were then routinely matched with new offences where DNA samples were present at the scene of a crime. One woman who gave a DNA sample in 2016 was later implicated in a 2021 burglary and criminal charges followed. After an outcry, the charges in that case have been dropped and the woman is now suing the city.
In another case with wide ramifications, police access to commercial DNA databases has been severely restricted following the use of the latter to investigate not just murder, which is widely supported, but also the much lesser offence of assault.
Clearly, prosecuting authorities must balance the scope for a successful prosecution in an intrusive offence like burglary (burglary, especially in the US, can go badly awry and escalate into serious violence) against discouraging women from coming forward, and therefore preventing successful prosecutions, in respect of what may well be far more serious offences against the person. But they also have to consider the extent to which they can carry public support. It’s clear that the Golden Gate Killer case has shown big public support for using DNA databases to catch people who have committed henious crimes; equally clear that using the same techniques to solve lesser crimes leads to widespread fears about anonymity and overweening state power.
This latter objection is usually framed in terms of fears of the use of a creeping assault on human freedoms and concerns that by uploading their DNA data to commercial websites people will implicate their relatives in offences. Commercial DNA service providers are obviously also worried that people will decline to sign up through such fears.
It’s worth remembering, however, that in most countries a large minority of people have criminal convictions; most of these folk are men so the likelihood of any one man having a conviction is quite high. Amongst some groups of men, a majority are or have been in the justice system. With offences below the most serious, such as murder and rape, people usually commit quite a few before or after they get caught. And of course, some people never get caught at all. It’s no wonder, therefore, that a lot of people are nervous about scope for people to be pursued for relatively minor offences through DNA provided to commercial databases like Ancestry.com by their uknowing relatives.
Politicians are also aware of the societal risk involved in using DNA to potentially considerably increase arrest rates amongst some groups. Even the cops and other authorities must wonder what would happen if lines were not drawn somewhere. Prosecution rates for lesser crimes like burglary are notoriously low: Could present systems handle the vast increase implied by the much more widespread use of DNA to solve such crimes?
There are no hard and fast answers to how this should all progress. It’s largely a question of public values and this will play out over time through. The cops, whose job it is to protect the public by solving crimes will understandably press for the increasing use of DNA. They’re likely to see complaints by offenders about being caught as carrying little moral weight. The justice system might tend to agree; so might the civil system. For example, we cannot know if the woman in the San Francisco case is guilty of any offence, but DNA evidence submitted by the prosecution is usually very strong. The San Fransisco case seems a poor call by prosecutors, but plaintiffs who have likely (on the balance of probability) committed a fairly serious offence will have an uphill struggle to convince courts to be outraged on their behalf about the way they were caught.
Prosecutors will be more political (small ‘p’, but in the US sometimes large ‘P’ too) than the cops. But they’ll be led and constrained by legislation and legislators have, for the large part, not yet begun to seriously engage with the issue. It may need to evolve a little further before they can.
In the meantime, the respective forces will press ahead. Cops will look for court orders to pursue data-holding companies and campaign groups will condemn cases, perhaps like the San Fransisco case, which seem to move too far ahead of the descending lava line. But shift it will, and at some point there will need to be decisions made by legislators.
To hazard a guess about how things will go, it might be worth considering this:
In places like the UK, with vast CCTV coverage, minor offences like speeding on the road have very high rates of successful prosecution. The public is often irritated by this. When caught, people often complain that cops spend all their time catching drivers doing 35mph in a 30mph zone and not much time catching the people who break into their houses. Indeed, it’s often pointed out that cops’ protocols often involve barely taking much action at all after a burglary where no-one was hurt. This arises as a consquence of resource constraint and the difficulty of catching burglars and so forth. Speeding fines are not anywhere, of course, so there might be a lot more public support for action on the other side of the balance sheet. The use of DNA on lesser offences like burglary might therefore have a lot more public support than we might at first imagine.
