Forensics: crisis, what crisis?
By Geir Madland on 14/05/15Share:
A recent three-part series on BBC Radio 4 sought to investigate the perceived loss of confidence in forensic science and how it might be reversed. Forensics in Crisis is currently available on iPlayer at www.bbc.co.uk/programmes/b05stg0j#auto.
Journalist Linda Geddes interviewed scientists, police chiefs and lawyers, and cited past cases involving forensics, to argue that problems have arisen in three respects:
1. Some forensic techniques are not sufficiently supported by data, i.e. there is an inadequate research base.
3. The presentation of forensic evidence in court is always a matter of subjective expert opinion, allowing interpretation and evaluation by counsel and jury.
Episode One, Crisis in Research, discussed miscarriages of justice that have resulted from evidence presented as scientific fact but unsubstantiated by research, starting with Barry Georgeâ€™s 2001 conviction for killing Jill Dando, which centred on a speck of gun residue found in his pocket. George was found not guilty at retrial, when it was agreed that the speck may have been transferred from firearms officers involved in the investigation.
In a second British case to undermine forensic evidence, former Scottish detective Shirley McKie was wrongly accused of visiting a murder scene. A subsequent inquiry exposed serious weaknesses in fingerprint evidence.
In the US, the flawed identification technique of hair morphology was used by the FBI to secure over 2000 convictions after which more than a dozen individuals have been executed. Donald Gates was convicted of murder on hair morphology evidence, an FBI expert claiming that there was a 1 in 10,000 probability that the hair came from anyone else but there was no data to support that. â€œThatâ€™s simply a made-up number,â€ said Peter Neufeld, co-founder of the Innocence Project. [See also News Round-Up, week ending 24.4.15: Guilty by a Hair in the News section of this site.]
A report by the National Academy of Sciences in 2009 concluded that bad science was to blame. Niamh NicDaeid, Professor of Forensic Science at the University of Dundee, said the NAS Report confirmed what many experts had feared, that there were deficiencies particularly in the interpretation of different findings, including fibre and hair examination. The same techniques are in use worldwide.
In the UK, hair analysis has been treated with scepticism, particularly since the development of DNA â€˜fingerprintingâ€™ by Sir Alec Jeffreys, but the closure of the Forensic Science Service in 2012 and its subsequent replacement by a private market has led to a dearth of research in the field.
Without research, often lengthy and costly, forensic techniques cannot be developed and validated. Tiernan Coyle, fibre analyst and owner of forensic firm Contact Traces, discussed the loss of a research budget. Naimh NicDaeid agreed, emphasising the particular need for a research basis when justice depends on forensic science. Former Labour MP Andrew Miller voiced concerns over likely wrongful convictions resulting from the lack of regulation of private forensic laboratories, the lack of coordination of primary research and the fragmentation of analytical work in individual cases. Inside Justice is aware that funding is available to police units; the Metropolitan Police won a bid for Â£6million for forensic research from the Police Innovation Fund last year but it is the small independent labs, undertaking defence and appeal work, with specialist techniques that canâ€™t compete in the current climate.
In the US, the vast majority of forensic work is handled by police-run laboratories. In the UK there are growing concerns over in-house testing and prosecution-bias. The second Radio 4 programme, Crisis in the Lab, described how established but expensive forensic techniques are falling by the wayside in favour of fingerprinting, DNA profile matching and digital forensics.
Predatory paedophile Umesh Kulasingham was eventually convicted with forensic textile techniques, the use of which may be dying out. One expert spoke of her fears for the future: â€œI think forensic science will be increasingly dumbed down to such an extent that we will just be doing the absolute basics.â€
Fibre evidence, involving analysis of thousands of individual fibres, has been crucial in many high profile murder cases, including those of Damilola Taylor and Stephen Lawrence, and in the Soham killings. Tiernan Coyle was concerned that this field of forensics and others, such as toxicology, are under threat, with numbers of competent practitioners decimated. Part of the problem is access and testing of evidence by police in-house laboratories, not all of which are accredited and therefore may not have sufficient expertise in all forensic techniques.
An anonymous former police scientist considered the UK criminal justice system not best served with decisions over choice of technique being subject to budgetary constraints.
Professor Bob Green of the University of Kent concurred. Evidence is consequently going unchecked, meaning cases may be dropped and justice not served. Chris Sims disagreed, justifying in-house analysis, but Angela Gallop did not feel the police were best placed to objectively decide on submission of evidence for forensic analysis.
Interpretation of fingerprints, always in-house, is coming under the same accreditation processes as other forensic science, following cases like that of Shirley McKie.
Accreditation is compulsory for private labs but though police labs have to be accredited too, the system is less transparent on penalties for not doing so and the system does not cover everything, such as the selection of evidence for submission.
The third and final programme of the series, Crisis in Court, considered the potential for forensic evidence to be misrepresented or misinterpreted in court, citing the eventual acquittal of Amanda Knox and Raffaelle Sollecito of the murder of Meredith Kercher. Their earlier conviction hinged on DNA evidence. DNA matching is often held up as the gold standard of forensic identification but, as Tracy Alexander has explained in an earlier article for Inside Justice (DNA: Did Not Attend), it is not entirely objective and should never stand alone.
UCL Cognitive Neuroscientist Dr Itiel Dror conducted a study of objectivity in DNA matching and found it to be anything but, despite the advent of computer software programmes. Ian Evett, of Principal Forensic Services, described how interpretation of partial DNA profiles from real-life crime scenes is fraught with complications involving small quantities, degradation and contamination.
To obtain a DNA profile, highly variable regions in the sample are â€˜bookmarkedâ€™ and amplified, and peaks identified.
Rudi Guedeâ€™s fingerprint was found in Meredith Kercherâ€™s blood and his DNA found in the rented room where she was killed. Professor Peter Gill explained how DNA detection has improved since he and Alec Jeffreys first developed the technique. This improvement allowed prosecutors to identify minute traces of Meredith Kercherâ€™s DNA on a knife found in Sollecitoâ€™s apartment, the programme explained, despite no preliminary chemical detection of blood. Amanda Knoxâ€™s DNA was also found on the knife and this was evidence enough to convict the two, in combination with what the court accepted was contamination of an exhibit by Scene of Crime Officers; Kercherâ€™s bra clasp, with Sollecitoâ€™s DNA.
Linda Geddes also described the cases of Merseyside taxi driver, David â€˜Flakyâ€™ Butler, who spent eight months on remand for murder after transfer of his DNA, and Devonian Adam Scott, who was accused of rape after a forensic sample was contaminated with his. However, Professor Paul Roberts of the University of Nottingham maintained that much of scientific evidence is as good as there can be, but emphasised that no evidence is ever conclusive or infallible.
Peter Gill is convinced that a prosecution bias exists in the private market now in the UK, certainly with the emergence of streamlined reports which were designed to expedite results but which contain no expert opinion as to their weight and relevance. He ended with a warning:
This engaging BBC series may have exaggerated the issues of subjective opinion in DNA profile matching and erroneous results, but the consequences of closing the FSS as a money-saving measure, a subsequent private market with no budget for research, in-house police labs with prosecution-biased, budget-led forensic decisions and often without accreditation, and the misuse of streamlined reports as evidence in court, are likely to be grave.