While Dobson and Norris and their friends were murdering Stephen Lawrence on 22nd April 1993, his blood got onto their clothes. That was the evidence that enabled the Court of Appeal to rule that Dobson should be retried for the murder, despite his acquittal on the same charge in 1996 in the failed private prosecution brought by the Lawrence family. This was the evidence that persuaded the jury at the Old Bailey to find them guilty. The blood has been on the clothes all along. It was not until the police reinvestigated the case in 2007 that a forensic scientist discovered it. It escaped the attention of the first police investigation and the private prosecution. Forensic scientists have developed highly discriminating tests to work out how a bloodstain has been deposited, and this was one of the key issues at the trial. The defence suggested that careless handling of the clothing taken from the suspects and from Stephen Lawrence made it likely that his blood got onto their clothes by accident, during the investigation. The jury rejected that, and must have preferred the expert evidence which showed that the bloodstains were characteristic of fresh blood being transferred – which could only have happened during the attack.
The techniques are well-established and the trial broke no new scientific ground. There was nothing that could not have been put before a jury before – it was just overlooked. An explanation is called for. Some one will say that lessons have been learned.
The thing is, lessons have not been learned.
The dissolution of the Forensic Science Service (FSS) is a scandal in itself and it will be the cause of future miscarriages of justices – the wrong people will be convicted, and the right people will escape justice. At the same time, the higher courts continue to adopt a credulous approach to categories of supposedly expert evidence which has not been subjected to proper scientific scrutiny. The result of both developments? A real risk that juries will be presented with unreliable, dumbed-down ‘expert’ evidence and asked to make vital decisions based on it.
As the oversight in the Lawrence case shows, the FSS has not had an unblemished record. It took another hit in 2007 when a High Court Judge in Northern Ireland rejected its DNA evidence in the Omagh bombing trial (Hoey  NICC 49). But it has proved its worth and won a high reputation for excellence in numerous other cases. When it goes, individual police forces will have to use their shrinking budgets to select the cheapest provider of expert opinions for the case in hand.
No less an authority than Lord Justice Leveson has expressed serious concerns about the Court’s readiness to allow evidence to be treated as expert evidence without in-depth scientific authentication. In a speech to the Forensic Science Society in November 2010 he said:
‘There have been increasing concerns that in certain circumstances expert evidence has been incorrectly used, or too much significance has been ascribed to it. This problem was highlighted recently by the Court of Appeal (Criminal Division) in R v Atkins  EWCA Crim 1879. The Court noted three factors about expert evidence which should be borne in mind throughout. First, expert opinion is just that: an opinion. Second, experts need to know the limits of their expertise and have the integrity to inform the Court of those limits. Third, expert evidence should – indeed must – be submitted to robust testing, either by another witness in the same field or in relation to accepted scientific methodology for the science and statistical analysis for probability.’
However, the criminal courts have adopted a test for the admissibility of ‘expert’ evidence that is not based on an appraisal by scientific peers; such evidence does not always require a firm base of statistical research to give support to opinions in particular cases. The weight and reliability of such evidence are left to the jury to decide. Our courts have taken a very different approach from the USA, where the admissibility of expert evidence in a new or developing area depends upon a scientific consensus about its reliability. Here, that approach is thought to oust the Judge from determining the issue. Instead, we have the nebulous concept that opinions on a given subject are admissible under two conditions: (1) whether study and experience give the witness’s opinion an authority that the unqualified will lack; and (2) whether the expert has undertaken the necessary study or gained the necessary experience. This was the formulation by Bingham LJ in the case of Robb (1991) 93 Cr App R 161. Our Courts have rejected a ‘reliable body of knowledge or experience’ condition.
A good example of their approach is Otway  EWCA Crim 3 (in which the writer represented the appellant): a podiatrist said he recognized the appellant as the unidentified man said to be the offender, on security camera footage, by his gait and posture. There was no database and no peer review of the technique he used, but the Court of Appeal held that these were not required – in effect, the self-certification of the witness as an expert was enough.
This laissez faire approach has caused or contributed to at least three scandals: the use of Professor Roy Meadow as an expert on child mortality, until he was finally discredited in the appeal of Cannings  2 Cr App R 7; the use of ear-print evidence Dallagher  EWCA Crim 1903; and the use of a forensic lip-reader who passed muster with the Court of Appeal (Luttrell  EWCA Crim 1344) but was later found to have given misleading evidence about her qualifications. All these cases concerned experts used by the prosecution. They suggest a degree of willed credulity on the part of the judges, together with a proprietorial reluctance to let other experts have a say on whether evidence is fit to be admitted. The reported cases offer reassurance on the impossibility of obvious quackery like soothsaying or astrology being admitted, but that is an aunt sally. It’s the better disguised fakers and incompetents who need to be kept out. The three cases above show that the present rules are not good enough to ensure that unreliable and dangerous evidence, wrongly labeled expert, is kept out.
The Court of Appeal has not been consistent. When it considered an expert relied on by the defence in the appeal against conviction in Gilfoyle  2 Cr App R 5, came close to insisting on the ‘reliable body of knowledge or experience’ condition for admitting the evidence – which they found wanting. Mr Gilfoyle’s wife was found hanged at the family home. G was convicted of her murder. He sought to adduce evidence of a psychologist about her likely mental state, to support the defence case that she killed herself. As readers of www.thejusticegap.com will know, Mr Gilfoyle is now trying to reopen his case, on the basis that the prosecution failed to disclose vital information about his wife’s precarious mental state and previous suicide attempts. So it looks as though the Court may have drawn the line too tightly and excluded reliable evidence which would have helped the jury to decide where the truth lay. Why should a jury have not had the same opportunity to assess it in Mr Gilfoyle’s case, as they were given in the cases decided the other way? Or why should the Judge have not used applied the “reliable body of knowledge or experience” criteria in the other cases, and used them accurately, to ensure that justice was done?
So the Lawrence case shows us that even experts can miss evidence that yields to routine analysis and can prove the case one way or the other; the demise of the FSS removes a body of experts of world renown; the prevailing laissez faire attitude of the higher Courts to new and under-researched types of expert evidence leaves the field open to plausible quacks and incompetents.