Forensic Science – How much faith should we put in a broken justice system?

So yeah, I’m slightly late to jump on the wagon of criticism to the justice systems regarding hair analysis but here we go!

CSI: Have You Ruined Forensic Science?

 In April, the news hit the mainstream media that the justice department and the FBI stated that ‘nearly every’ examiner in the forensic units gave flawed testimonies in almost all trials. The experts overstated a ‘match’ in more than 95% of the nearly the 270 trials; favouring the prosecution. Of these, 32 of which were to serve the death penalty, 14 of which were killed. There is probably more to come, as the inquest is into 2000 cases overall. 

“The Justice Department and FBI have formally acknowledged that nearly every examiner in an elite FBI forensic unit gave flawed testimony in almost all trials in which they offered evidence against criminal defendants over more than a two-decade period before 2000.

Of 28 examiners with the FBI Laboratory’s microscopic hair comparison unit, 26 overstated forensic matches in ways that favoured prosecutors in more than 95 percent of the 268 trials reviewed so far, according to the National Association of Criminal Defense Lawyers (NACDL) and the Innocence Project, which are assisting the government with the country’s largest post-conviction review of questioned forensic evidence.”

If this is on the whole a massive shock to you, then you really have too much faith in forensic science. The society we live in today expects a wide array of no holds barred forensic investigative techniques to any crime committed, more so in murder trials. As a student of forensic science, we are constantly (and rightly so) berated with the term ‘CSI effect’. This is the term used to describe how people put way too much stock and faith into forensic science due to the show, as the name suggests, Crime Scene Investigation. The ‘scientists’ on this show use whatever means necessary to obtain any information from trace evidence; instilling a false sense of security in any forensic evidence.

Subjectivity

Now, I’m not stating that all forensic evidence is wrong per sae, but should come under much more scrutiny. When subjective evidence is found, much criticism should be used to avoid biases, most of which (I’d like to think) are more unintentional cognitive biases, rather than intentional misconduct. Hair analysis occurs subjectively, not much technical work is imparted into its analysis. Simply, a microscope is used to observe the hair structure. Thus, the problem with hair analysis is the overestimation of confidence placed on the ‘matches’ between a hair at a crime scene and the hair obtained from a suspect. Hair shows a large morphological variation: even in the same person.  The structure of hair is relatively simple, consisting of the medulla in the centre, the cortex surrounding it and then the ‘outer’ cuticle.  These ate the three features which are examined under a microscope – observing the colour and patterns.

  

If the hair sample is found to be a ‘match’ that does not conclusively state that the hair sample came from only that individual – there could be a match to many more people. This means that there are a rather large number of false positives, which is seen here with the FBI. This is most certainly not limited to hair analysis; any subjective work will have a large number of false results. For example, take the work of Itel Dror, who went back and told fingerprint examiners that they had made a miss-identification and people had been proven innocent or guilty due to other evidence. Most examiners changed their view on the fingerprints; finding a match if they were told that the person did commit the crime (after previously stating no match without this information) and finding no match when told the person did not commit the crime (after stating a match without this information). This kind of bias, of course, has been brought up to higher forensic science regulators which suggest lines of debiasing techniques, such as the National Academy of Sciences (NAS) or over here in the UK: House of Commons Science and Technology Committee (SciTech) who partially suggest lines of scepticism towards more vigorous analysis of subjective evidence.

Conclusion

As we start a new government solely dedicated to a conservative party, what more will be done with a broken justice system? People have asked questions on the stance of forensic science prior to the General Election, yielding very little results; only UKIP and TUSC responding, which is very disconcerting.  

My main point here is; this isn’t new news. Biases have been known for many years, why has it taken so long to review the cases involving subjective evidence? Hair isn’t the only case here, we have bite marks, tyre marks, ballistics, handwriting, shoe marks, ear prints and as mentioned, fingerprints. Subjective analysis is a massive problem within criminal justice systems around the world’ leading to false convictions and mistrials. It’s excellent that this problem is gaining more media attention, highlighting the transparency that sciences saliently needs, especially when brought into a courtroom. Juries will overestimate the evidential value of evidence due to the CSI effect and overstating of confidences by expert witnesses. It would be beneficial to the justice system if shows such as CSI will address these issues, but I highly doubt it will. Therefore, is it for the government or the scientists to address the issues? Scientists have tried, very much so, to address bias involved in forensic sciences, but are these working with the CSI effect so vigilantly in place?

I can't say I blame CSI exactly, they haven't claimed to be accurate in their glamorization of a grim subject, but they also havent been forthcoming with how forensic science is actually conducted and appear to have literally zero spending restrictions. This effect is a product of yearning. Yearning for belief that moral and unbiased people are trying to clear the names of innocents and incarcerate the law breakers, note here, that life most certainly does not imitate art.