DNA EVIDENCE

FORENSIC SCIENCE IN CRISIS – HOW IT OCCURS

Current criticism of the provision of forensic science in England/Wales deserves some examples.  Here are three recent ones that are representative of the sort of detrimental consequences of government policies and police practices that now afflict so many cases.

Case 1

A sex worker alleged that she escorted two men into an alley to discuss prices.  One male grabbed her head and neck, attempted to unbutton her trousers and put his hand inside her top.  She screamed and two passing officers apprehended the males.  They were charged with assault and their clothing was seized.  One male was found to have a condom on his penis.  He stated that he was having sexual intercourse with the complainant when she screamed and so he moved away just before he was apprehended.

The condom was initially submitted to a prosecution forensic service provider who advised that analysis could only benefit the defence.  On request it was returned unexamined to the police.  Release for forensic examination commissioned by the defence was prevented, but it was re-submitted to the prosecution forensic provider.

A particularly high quantity of DNA was recovered from material that included the type of cells that can be found lining a vagina and this gave a strong DNA profile matching the complainant.  Exactly what would be expected if they had sexual intercourse.

Appreciation of the evidential value of this result was then neutralised by an evaluation statement commissioned by the prosecution, that made no mention of the defendant’s account or that the results might support that account, but did assert that they could be explained by indirect transfer of her DNA to the condom via his hands; the implication being that the results fitted with the allegations.  A clear example of bias caused by inaccurate expert evaluation of forensic test results.  Evaluation should consider the likelihood of obtaining these results against both accounts, not simply provide an excuse for a result that does not support a prosecution.  But also misleading in itself, because the very high quantity of recovered DNA (more than on the reference mouth swab) made it extremely unlikely that the result could have occurred via the suggested secondary transfer.

It took an unnecessarily long journey to produce one DNA profile that was accepted to be very much more likely from defendant’s account than the allegations.

Case 2

In another recent case involving sexual activity between two teenagers on a grassy/muddy area, considerable forensic effort was put into testing intimate swabs and knickers for semen, despite there being no suggestion of ejaculation in either account.  Failure to detect any semen was therefore not surprising.  There were distinct differences between the accounts of how they knelt and lay on the ground, giving entirely different expectations for where mud stains might be on their clothing.  Considerable time, effort, expense and a court order were required to establish the merits of a forensic strategy that identified this examination as probative, with the work eventually commissioned by the defence and paid for via Legal Aid.  The results provided clear support for one of the accounts, but it still required the case to proceed to trial for resolution.

Case 3

A man was arrested for punching his estranged partner to the face and his jumper was seized as an exhibit because it appeared blood stained.  He accepted that he punched her because she was attacking him with kitchen knives, including stabbing or attempting to stab him to the back.  A simple ‘domestic’ which apparently did not warrant any forensic examination.  Initially there was considerable reluctance to release the jumper for examination, on the basis that its relevance to the charge was not understood.  Four clear stab cuts to the back of the jumper established its relevance.

How can it possibly be in the interests of quality justice to allow cases like these to proceed to court without even basic forensic expert input to answer the most obvious questions that Counsel or the jury might ask?

How can it possibly in the interests of victims to require them to give evidence at court, when probative forensic examinations frequently result in earlier resolution?

The victim of a false sexual allegation is the victim of a crime; a simple role reversal from the circumstances if the allegation was true.  How can it possibly be in the interests of justice to investigate only one account and resist as far as possible any forensic examinations that might provide contradictory evidence?  The DPP’s declared desire to increase convictions for sexual offences should be based on balanced and thorough investigation, not reliance on bias.

How can it possibly be cost effective to public funds, to delay these examinations, resist them or pass on the responsibility, or then try to circumvent their evidential impact?  These all delay justice.

The detrimental effects of the current crisis, in reduced cost effectiveness, inaccurate evidential impact and ineffective use of forensic science are obvious to any informed forensic practitioner and, in my experience, to many defence lawyers.  Repair of the system may require more resources, but more urgently it requires a strategy to improve collective effectiveness of all the fragmented and parochial components.  If it continues to be a battle between agencies to stretch their budgets as far as possible, the effect will continue to be wasted effort and expense; the collateral damage being that victims of crime and defendants are let down in greater numbers.

Dr Duncan Woods, Chief Scientist, Keith Borer Consultants