Identification by DNA on moveable objects


On 17th February 2017 in the case of R v Tsekiri [2017] EWCA Crim 40 the Court of Appeal ruled that where the sole evidence against a Defendant was his DNA profile on a moveable object found at the scene of a crime this can be sufficient to raise a case to answer.  This overruled what had been set out as the definitive position by the Court of Appeal in the R v Bryon [2015] EWCA Crim 997 in which the court appeared to rule that where a moveable item with mixed DNA profiles, one of which belonged to the defendant, was found at the scene, this would not be sufficient on its own to found a conviction.

The Court in Tsekiri stated that since the Court in Bryon had not been considering a case in which the only evidence against the defendant was his DNA profile on a moveable object found at the scene (the Defendant had a highly relevant conviction supporting the DNA findings) any observations regarding cases where the DNA evidence was the sole evidence were obiter.

Questions had been raised as to whether the case of Bryon, and the decisions that preceded it, were correctly decided in R v FNC [2015] EWCA Crim 1732.  This case dealt, not with moveable objects, but with DNA directly deposited during the course of the commission of an offence with a high DNA match to the defendants (semen on a pair of trousers during a sexual assault on the underground).  In that case however the Court observed that improvements in the analysis and techniques of analysis of DNA had improved markedly and so DNA on an article left at the scene may be sufficient to raise to case to answer where the match probability is very high.

The Court in Tsekiri had the opportunity to consider this very scenario.  The complainant was robbed as she sat in her car.  The robber handled the exterior driver’s door handle.  Swabs from the door handle revealed a mixed DNA result with a complete profile matching the Defendant.  The match probability was in the order of 1:1 billion.  The Defendant argued that as this DNA profile on a moveable object was the sole evidence against him, the case of Bryon was authority for his submission that there was no case to answer.  The Court agreed that this was the sole evidence against the Defendant (rejecting the relatively feeble Prosecution submissions that there was additional supporting evidence) but observed that there could be no sensible rationale for the principle that the DNA profile on an article left at the scene, unsupported by other evidence, was insufficient to found a conviction.  In fact this was inconsistent with the approach taken by the Court of Appeal in cases of facial mapping (Hookway [1999] Crim.L.R.750; Weighman [2011] EWCA Crim 2826).  The Court distinguished the present cases from the cases preceding Bryon on the basis that either the match probability of the DNA profile was lower and therefore the possibility of error greater (R v Grant [2008] EWCA Crim 1890) or the case turned on its own particular facts (R v Ogden [2013] EWCA Crim 1294).

The Court ruled that the fact that DNA was on an article left at the scene of a crime can be sufficient of itself to raise a case to answer where the match probability is 1:1 billion of similar and that there is no legal or evidential principle preventing a jury from considering such a case.  Whether such evidence would be sufficient to raise a case to answer will depend on the facts of the particular case.  The Court set out the following (non-exhaustive) list of factors to be considered when considering whether the DNA evidence in and of itself was sufficient:

  1. Is there any evidence of some other explanation for the presence of the Defendant’s DNA on the item other than involvement in the crime?
  2. Was the article apparently associated with the offence itself?
  3. How readily moveable was the article in question?
  4. Is there evidence of some geographical association between the offence and the offender?
  5. In the case of a mixed profile is the DNA profile which matches the Defendant the major contributor to the overall DNA profile?
  6. Is it more or less likely that the DNA profile attributable to the Defendant was deposited by primary or secondary transfer?

It seems likely that this will remain the definitive position of principle since any advances in DNA analysis (for example advances establishing unique DNA profiles for every individual) will remain subject to the same evidential considerations identified by the Court of Appeal in individual cases.


Rebekah Hummerstone