Julian Washington v R (Bermuda)

A criminal conviction based materially on flawed expert DNA evidence is unsafe where the analysis uses an artificial composite profile, unsupported assumptions, unreliable statistical treatment or the prosecutor’s fallacy. Fresh expert evidence should be admitted where it exposes such flaws and admission is in the interests of justice. Expert witnesses must provide independent, objective assistance, state the assumptions underlying their opinions, consider material facts that detract from them, identify limitations in their expertise and data, and disclose material changes of view. Those instructing experts and trial judges must ensure that these standards are understood and discharged.

The appellant was convicted in Bermuda of murder, attempted murder and firearms-related offences. The prosecution case depended principally on DNA evidence said to place his DNA on bullet casings and gunshot-residue evidence. The respondent later accepted that the DNA evidence was flawed and did not seek a retrial.

The Privy Council considered whether to admit fresh expert evidence concerning the DNA analysis, whether the convictions were unsafe, and whether the appellant was entitled to written reasons despite the parties’ agreement that the appeal should succeed. The Board also addressed the duties of expert witnesses in Bermuda and the review of other cases involving the same laboratory.

1. Disposition. The Board advised His Majesty to allow the appeal, admit the additional DNA ground and fresh expert evidence from Dr Krane and Dr Llewellyn, and quash the convictions and sentence. The Board had previously ordered the appellant’s release on unconditional bail.
2. Fresh evidence and unsafe convictions. The fresh reports identified significant flaws in the DNA evidence relied on at trial. The four casing swabs had been treated as a composite sample without addressing whether they had a common source. Results from multiple inconsistent amplifications had been aggregated, with a risk of including artefacts. The interpretation appears to have used suspect-centric assumptions, including assumptions about allelic drop-out, and omitted results capable of excluding the appellant.
3. Statistical evidence. The combined probability of inclusion calculation was unreliable because the sample was a low-template mixture with an unknown number of contributors and possible allelic drop-out. The statistic of one in 46 million was therefore inflated and was wrongly presented as equivalent to the probability of innocence, engaging the prosecutor’s fallacy identified in R v Doheny [1997] 1 Cr App R 369. The evidence should have been characterised as inconclusive.
4. Expert duties. The Board reiterated, following Myers v The Queen [2015] UKPC 40, that an expert must give independent and unbiased assistance, state the facts and assumptions supporting the opinion, consider material facts against it, identify matters outside the expert’s expertise, disclose insufficient data and provisional conclusions, and communicate material changes of view. The duties apply in criminal proceedings. Instructing lawyers must bring the applicable standards to foreign experts, and trial judges must be satisfied that the standards have been recognised and discharged.
5. Wider review. The Board recorded the Director of Public Prosecutions’ transparent review of other cases involving DNA analysis by Trinity DNA Solutions, but held that the scope and conduct of that review were matters for the DPP and could not be directed by the Board.

• Privy Council: The Board granted permission to appeal on all grounds except possible jury bias, admitted fresh expert evidence, advised that a miscarriage of justice had occurred, and quashed the convictions and sentence.
• Court of Appeal for Bermuda: The appellant’s appeal against conviction was dismissed on 17 May 2016. No citation was stated.
• Supreme Court of Bermuda: The appellant was convicted after trial between 21 April and 6 May 2014 and sentenced on 19 September 2014 to life imprisonment with an overall minimum term of 30 years.