Reed & Anor, R v

Scientific expert evidence is admissible where its basis is sufficiently reliable. It is not subject to an enhanced admissibility test. The judge determines admissibility when it is challenged, and the jury assesses competing admissible opinions.

A suitably qualified forensic scientist may, with clear caveats, enumerate and evaluate possible mechanisms of DNA transfer where the profile and other evidence provide a sufficient basis. The expert may not speculate about the accused’s use of an object where that conclusion lacks a scientific foundation. Expert disagreements must be identified and managed before trial under the Criminal Procedure Rules.

David Reed and Terence Reed appealed murder convictions from the Crown Court at Teesside. The prosecution relied in part on DNA profiles recovered from fragments of two knife handles found near the deceased. The issue was whether the forensic scientist could evaluate primary and secondary transfer of unidentified cellular material, and whether fresh expert evidence should be admitted.

Neil Garmson appealed convictions from the Crown Court at Stafford for kidnapping, rape and sexual assault. He challenged the admission and presentation of mixed and partial DNA-profile evidence, and also sought to adduce fresh expert evidence.

The central issues were the admissibility and proper evaluation of DNA evidence, the control of expert evidence, and whether any alleged errors rendered the convictions unsafe.

1. The appeals were dismissed. The convictions of the Reeds and of Garmson were safe.

2. Scientific expert evidence is inadmissible if its underlying basis is insufficiently reliable, but English law imposes no separate enhanced threshold for new science. If the court is satisfied that the evidence has a sufficiently reliable basis and is within the expert’s proper field, opposing views ordinarily fall to be tested at trial. The party tendering challenged expert evidence must establish its admissibility.

3. The court gave guidance, although the general challenge had been abandoned, that Low Template DNA profiles may be reliably interpreted where the DNA quantity is above the stochastic threshold, then thought to lie between 100 and 200 picograms. A general challenge to the validity of the FSS LCN process in such a case should not be permitted without properly advanced new scientific evidence. Cases within the disputed threshold range require case-specific expert evidence.

4. Where the DNA quantity is over 200 picograms, an appropriately qualified forensic scientist with relevant scene-of-crime experience may enumerate and evaluate possible primary and secondary transfer mechanisms. The scientist must make the limits of the science clear and must have a sufficient evidential basis in the profile, the scene and other agreed facts. Valerie Tomlinson could therefore evaluate whether the appellants’ DNA was more likely to have arrived by primary or secondary transfer. Her opinion that they were handling the knives when they broke lacked a reliable scientific basis and was inadmissible, but that impermissible gloss could not have affected the verdicts.

5. Under Criminal Procedure Rules Part 33, expert reports must identify material ranges of opinion and qualifications. Disagreements should be brought before the court, ordinarily followed by an experts’ statement under Rule 33.6. This enables the judge to separate issues of admissibility from issues for the jury.

6. The court declined to admit the proposed fresh expert evidence under section 23 of the Criminal Appeal Act 1968. The material was available at trial or did not undermine the safety of either conviction. The Reeds’ remaining complaints about the summing up were rejected. In Garmson’s case, the judge had fairly explained the limits of the partial DNA evidence and directed that it could not alone prove guilt.

• Court of Appeal (Criminal Division): Reed & Anor, R v [2009] EWCA Crim 2698. Appeals against conviction dismissed.
• Crown Court at Teesside: David Reed and Terence Reed were convicted of murder on 7 August 2007.
• Crown Court at Stafford: Garmson was convicted on 20 August 2007 of kidnapping, rape and sexual assault offences.