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    in focus

ruth morgan: changing the focus of forensic science

Forensic science technology has become so advanced that analysts can trace gunshot residue from a crime scene to a potential murderer. But what if a murderer, say, shakes your hand? What if they ride the bus, and transfer incriminating evidence to every person who sits in their seat over the course of a day… including you?

“Misinterpretation of evidence is the biggest challenge that forensic science is facing,” according to Ruth Morgan, Professor of Crime and Forensic Science at UCL and Founder and Director of the UCL Centre for the Forensic Sciences; dedicated to addressing the biases and shortcomings of interpreting forensic science evidence. “If forensic science doesn’t change,” stated Ruth in her me Convention talk ‘Minority Report: Forensic Science and its Future’, “forensic science isn’t going to be ready for the future.”

the turning point

One case, in particular, opened Ruth’s eyes to our challenges in understanding forensic science evidence, and the tragic repercussions of false assumptions. In a 2002 murder trial, two men were deemed guilty of murder based on purportedly rare particles that were found on the victim’s body, and in their vehicle. Because these particles were thought to be rare, and because it was presumed that these particles could only last on the victim’s clothing for a short amount of time -- a matter of minutes, perhaps -- it was deduced that the victim must have made contact with their car seat shortly before being killed. In follow-up experiments, however, Ruth realized that these particles were actually incredibly common: They derive from disposable cigarette lighters, and 4,000 particles are released every time one such lighter is flicked on. What’s more, 20% of these particles lingered on test clothing for upwards of 18 hours… far longer than the mere minutes scientists had assumed. Because of prejudicial inference, these two men were wrongfully imprisoned for years.

Stocksy/Victor Torres

And it gets worse. In 2015, the FBI determined that in 96% of cases they had examined where hair analysis (wherein hair found at a crime scene is inspected under a microscope and traced back to a suspect: You’ve likely seen it on CSI.) was critical, the evidence had been misinterpreted. In 35 of these cases, the supposed criminals were subject to the death penalty. Last year, a UK study found that 22% of the cases upheld by the UK Court of Appeal had been misinterpreted. Ruth goes into more detail about grave errors like these in her article for The Guardian, and in her stunning me Convention talk.

Forensic science ultimately comes down to these two questions: How and when does evidence interact with its environment? And equally important, what kind of factors are impacting human decision-making in the lab, at the crime scene, and in court? Well-funded cutting-edge technology helps us comprehend the first question. Answers to the second question, however, are strongly impacted by cascade bias; a self-reinforcing cycle of judgement that determines what is examined and how it gains relevance. For instance, when a male corpse is wrongfully deemed female because of the clothing it wears, the subsequent court ruling is based on an inaccurate sex determination. Unfortunately, social conditioning and cascade bias do not receive the same enthusiastic analysis or funding as technology.

accounting for bias

The UCL Centre for the Forensic Sciences, with Ruth at the helm, aims to remedy these dangerous biases by studying cognitive issues and potential solutions. For example, The UCL Centre team is researching the role that societal conditioning plays in the evaluation of skeletal remains, like the aforementioned male skeleton in female clothing; as well as targeting fingerprint sufficiency decision-making (the assessment of whether or not a recovered fingerprint is of good enough quality to be used for identification purposes). And in order to stop cascade bias from reaching the courtroom, Ruth and her colleagues have been heavily researching use cases for the Bayesian Approach: A model that answers questions about the existence of a cause given the existence of an effect. This probabilistic way of thinking helps to keep forensic scientists from making assumptions they are socially conditioned to make.

Stocksy/Per Swantesson

“Our sole focus cannot be on developing new technologies,” says Ruth. We must focus on other factors influencing decision-making, and we need data that informs the interpretation of what a piece of evidence ultimately means. We need a forensic science community that includes different philosophies. “That will create a community where people ask: ‘What if?’”

me Convention speakers and attendees, too, make up a community of people who ask ‘What if?’. What if we challenged social conventions, pursued awareness of our own biases, and actively diversified our given industries? In the case of forensic science, diversity of perspective can be a life or death issue. To change the future of forensic science, and thus the future of countless individuals affected by criminal investigations, we need to ask good questions first – and we also need to be able to question these questions.

Watch Ruth’s full talk: Minority Report: Forensic Science and its Future. And subscribe to our newsletter to stay in the loop about upcoming me Convention events.

Disclaimer: The views of me Convention speakers do not necessarily reflect the opinions of either Mercedes-Benz and/or SXSW.