focus on Forensics DNA: its Place in the Criminal Justice System Tracy Alexander BA(Hons), MSc, Cold Case Review Manager, LGC HQ, Room A018, Teddington, Email:
Tracy.Alexander@
lgcforensics.com
The fi nal part of this series* looks at how the use of DNA profi ling has contributed to the Criminal Justice system, but also at the changes that use has brought about. DNA evidence has become a fundamental part of the presentation of evidence in criminal trials, though it has its place in other scenarios.
Historically, evidence of identity was limited to that of a direct eye witness, with all the inherent pitfalls that created. With the coming of photography came the possibility of capturing and keeping an image, and the development of fi ngerprint identifi cation further enhanced the possibility of a criminal being identifi ed from the traces he or she left behind. The Fingerprint Bureau was set up in the UK in 1901, with the fi rst conviction employing this technology being for a murder in 1905.
The fi rst paper reporting the use of DNA in a criminal context was published in 1985 by Alec Jeffreys, Professor of Genetics at Leicester University. Jeffreys was researching inherited variation in human DNA and he demonstrated how a DNA profi le could be used to resolve issues of identity and kinship. Its initial use in legislative practice was to demonstrate that a child was the legal offspring of two individuals already granted asylum in the UK, and therefore entitled to remain.
The fi rst use of DNA in a criminal investigation came in the following year, when Professor Jeffreys contributed to the solving both of a murder and of a ‘cold case’. In 1983 Lynda Mann had been found raped and murdered on a deserted footpath in Leicestershire. Conventional grouping tests on semen samples from the body suggested that her killer was a person with blood type A and an enzyme type shared by approximately 10% of males in the general population. With no further evidence the case remained unsolved. In 1986 the murder of another girl, also in Leicestershire, was linked by police through modus operandi. Police held a prime suspect, Richard Buckland, who confessed to the second murder but not the fi rst. Jeffreys, in conjunction with the Forensic Science Service, using extraction methods which enabled DNA from semen to be separated from DNA from vaginal cells, demonstrated that the murders were committed by the same person and that that person was not Buckland. Leicestershire Constabulary and the FSS began an investigation in which 5,000 local men were asked to volunteer blood or saliva samples, but after six months no matches had been found. Later one of those men was heard bragging that he had been paid £200 to give a sample on behalf of a man called Colin Pitchfork. Pitchfork was arrested in September 1987 and samples taken from him matched those of the double killer. Pitchfork admitted the murders and was convicted in 1988, becoming the fi rst man to be convicted on DNA evidence, with Buckland being the fi rst person to be proved innocent by DNA profi ling. It was also the fi rst time that the mass DNA screening of a population had been undertaken, a process that has been carried out on numerous occasions since. Even in cases where no suspect has been identifi ed through this process it has been benefi cial in quickly eliminating a large number of individuals from the investigation.
Legislation
In the UK, a Royal Commission was set up in 1993 to look at the opportunities that new DNA technologies might be able to offer the criminal justice system. The ability to copy and therefore multiply samples meant that regions of DNA could be replicated simultaneously, but the possibilities of this new technology were limited by restrictions in the Police and Criminal Evidence Act. PACE1984 had been specifi c about the consent and authority required before a sample could be taken. Samples were categorised as ‘intimate’ or ‘non-intimate’ and regulations covered who could and could not take samples. The Criminal Justice and Public Order Act 1994 redefi ned intimate and non-intimate samples: mouth swabs were redefi ned as non-intimate and could be obtained without consent. Though a suspect could refuse to open his mouth, it was then permissible to pluck head hairs with roots from which DNA could be obtained. Consent was still required to obtain blood and still required a qualifi ed practitioner to take it. The Police Reform Act (2002) changed the regulations concerning the taking of samples: a police constable could now take non-intimate samples, or could delegate this power to a ‘designated person’ such as a civilian forensic offi cer. It also created the requirement for all new police offi cers to supply DNA samples to the Police Elimination Database.
In 1995, the evolution of technology and the subsequent change in legislation meant that the Home Offi ce was in a position to create a database. The technology was simplifi ed and automated, and the world’s fi rst criminal intelligence database was launched in April of that year: the UK National Criminal Intelligence DNA Database (NDNAD). Scotland and Northern Ireland have databases separate to that in England and Wales.
In the UK, legislation regarding the collection, storage and use of data held on the NDNAD has developed over time, and no single piece of legislation covers every aspect Legislative amendments have been made to old laws, and case law originating from judges’ rulings has re-defi ned the application of the legislation.
The Doheny and Adams ruling (1997) addressed the way in which DNA evidence should be presented in court. An expert could no longer give an opinion on whether a crimestain came from a suspect, but had to explain its probability. In 2000, the Lashley judgement in the Appeal Court ruled that DNA evidence alone was insuffi cient to bring a conviction and supporting evidence was also required. However, this can be as limited as geographical proximity to the offence; living in or having visited the region where a crime scene stain is matched can be enough. Furthermore, in 2000, challenges to convictions in two cases, R v Wier (murder) and R v ‘D’ (rape), sparked further reform. PACE (1984) required samples to be destroyed after acquittal or discontinuance; Wier and ‘D’ were identifi ed using unlawfully held DNA samples.
The convictions were appealed, but the Lords found that it would have been against the cause of justice for the convictions to be set aside, and the Criminal Justice and Police Act 2001 amended PACE so that now all DNA data collected from persons arrested for an offence could be kept, whether found guilty or not guilty. The Criminal Justice Act (CJA) 2003 further extended this so that data could be logged from anyone arrested for an offence, irrespective of whether they were eventually charged.
Slides “sperm heads can still be visualised on old slides with an AP+ reaction” Credit: CathyTurner
Within a short space of time the database doubled in size, but the problem of holding records of innocent people was created. Samples and profi les could only be destroyed by application to the Chief Constable of the arresting force. In addition, the holding of samples for the prevention or detection of crime is exempt from the Human Tissue Act (2004), brought about in part as a response to the discovery of the retention of the organs of children without consent by the Alder Hey Children’s Hospital.
INTERNATIONAL LABMATE - MARCH/APRIL 2014
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