The case for a national DNA database

A woman was raped in front of her three children on the Lahore-Sialkot motorway. The main culprit was identified based on DNA evidence. The police got lucky this time, as they found a match with the DNA database maintained by Punjab Forensic Science Agency (PFSA). But the probability of finding a match was extremely low, considering the database merely had 27,000 profiles in a country of 220 million people. What would have happened if the culprit’s record hadn’t existed from a prior case? This could have ended up like many such dead-end cases.

A forensic DNA database can have millions of records collected from convicts, suspects or even the general population and can be used to cross-match evidence collected from a crime scene. Even a partial DNA match can help the police in narrowing down its search, since close relatives share parts of a DNA sequence. Research shows these databases can greatly help in crime reduction, absolving the innocent and solving the dead-end crimes.

Different countries have taken different approaches to build their national forensic DNA databanks. In the US for instance, it is now mandatory to test all arrestees, even before they are convicted of a crime. The US DNA database now has 19+ million profiles. Similarly, in the UK, the police can take DNA samples without consent from anyone arrested on suspicion of any recordable offence and now has access to 5+ million profiles. On the other hand, countries like Kuwait and the UAE are building DNA databases of their entire population.

Then why don’t we expand our DNA database?

Before these large-scale national forensic DNA databases can be created, however, there is a need to promulgate supporting laws, empowering the government for wider DNA testing and laying down data storage, access and use protocols. Pakistan unfortunately doesn’t have any such law, which is an essential pre-requisite. Secondly, our legal framework is also weak, when it comes to use of DNA in court. Although DNA evidence is admissible in case of sexual offences, it is treated as secondary or corroboratory evidence, preventing its use as primary evidence.

Besides a robust legal framework, these DNA databases also need sophisticated technical capacity. Fortunately, we do have such capacity in Pakistan. PFSA is a state-of-the-art facility, having topnotch DNA and serology analysis capability. The agency is already assisting the federal government and other provinces in setting up similar facilities and this capacity can easily be beefed up.

But doing this is easier said than done. DNA testing and storing profiles for a long term are expensive. For instance, in 2010 each DNA profile cost around £30-40, while storing it on the database cost about £1 a year, besides policing and other peripheral costs. This means that as forensic DNA databases are expanded, the costs can be substantial. Notwithstanding the fact that these costs are coming down over time, due to technological advancements, this calls for significant resource allocation for this purpose.

Other issues surrounding the use of DNA evidence include false matches, misinterpretation of evidence from crime scenes, degradation of DNA samples and risks of planted evidence. Although the probability of false matches is generally low, it could still happen. Similarly, careless handling of evidence can contaminate the sample or can lead to errors. Improvement in crime scene protocols, ensuring chain of custody for the evidence, quality assurance protocols in handling and testing of evidence, and training of police and judicial officers are critical in building credibility of DNA evidence.

Every time a gruesome sexual crime happens, we wake up to the need for having a comprehensive DNA database. Establishing a forensic DNA databank could be a game-changer for reducing sexual offences in Pakistan but unfortunately it stands nowhere on the radar of the policymakers.

Published in The Express Tribune, September 22^nd, 2020.

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