DNA evidence, a double-edged sword

Most people believe they could never be convicted of a crime they did not commit. They believe that if they were falsely accused, the “system” would discover that they were not guilty and the charges would be dismissed.



This is the same system that produces hundreds of wrongful convictions every year, that is more interested in metrics and throughput of prosecutor’s offices and courts, and that virtually every month produces some horror story of failure, abuse and negligence. They must be very trusting, indeed.

For instance, DNA evidence has revolutionized forensic science. When done properly, it can provide compelling evidence, both to prove guilt and to exonerate the innocent, especially with serious crimes like those involving sex or murder. 

But the problem with DNA evidence, like all other technology, is how it is used by humans. Fallible humans, who may be lazy, poorly trained, incompetent, or pressured by police and prosecutors to arrive at the answer they want them to arrive at. DNA evidence has been used to convict innocent individuals.

To some, the solution is more technology. The development of automated DNA testing equipment has occurred and law enforcement is buying these machines. But because some are sold by businesses who plan to make money, the source code is secret. This means we really have no idea how accurate the system is when producing results, so it boils down to us having to trust the manufacturer, who is operating with profit in mind.

Given the sorry status of many crime labs and forensic testing in general, an automated machine could be an improvement to the current system. But the source code will need to be accurate, transparent and verifiable.

Without such safeguards, we are merely exchanging one broken and flawed process for another and will continue to see more cases of bad convictions. For those who believe that could never happen to them and they, therefore, have no interest in this issue, remember, every time the wrong person is convicted of a crime, it means a guilty person has gone free.

Source: theatlantic.com, “The False Promise of DNA Testing,” Matthew Shaer, June 2016