Cannings, R v

Where several infant deaths in one family remain unexplained, their rarity does not establish that they were caused by deliberate harm. Excluding known natural causes leaves the cause unknown; it does not reverse the burden by requiring a parent to provide a convincing natural explanation.

Where the prosecution depends exclusively or almost exclusively on a serious dispute between reputable experts, and natural causes remain a reasonable possibility, a murder prosecution will generally be unsafe without cogent evidence outside the expert evidence tending to show deliberate harm.

The appellant was convicted at Winchester Crown Court of murdering two infant sons, Jason and Matthew. The Crown alleged that she had smothered them and relied on the deaths of a third child and on life-threatening episodes involving the children as a pattern of deliberate harm.

The appellant denied harming any child. She contended that the deaths were natural but unexplained sudden infant deaths. On appeal, the court received significant fresh expert evidence, including evidence bearing on recurrent unexplained infant death, possible genetic factors, and the significance of the intervals between apparent health and collapse.

The central issue was whether the fresh evidence and the proper approach to the expert evidence left the convictions safe.

1. The appeal was allowed and both convictions were quashed. The court held that the convictions were unsafe because the expert evidence was critical to the Crown’s case and its fundamental premise had been demonstrably undermined by significant and persuasive fresh evidence.

2. Multiple unexplained infant deaths in one family are rightly a matter for the most rigorous investigation. They do not, however, identify deliberate harm as their cause. The exclusion of presently known natural causes does not prove smothering or other unlawful violence. If, after proper investigation, no cause is established, the deaths remain unexplained and cannot properly be treated as criminal deaths merely because they are rare.

3. The fresh evidence materially weakened three propositions central to the Crown’s case: that three natural unexplained infant deaths in one family were effectively inexplicable; that a short interval between an infant appearing well and being found dead strongly indicated smothering; and that an earlier life-threatening episode pointed towards deliberate harm. It also established a realistic, though undefined, possibility of a genetic explanation within the family. The court could therefore not be sure that the deaths were not natural.

4. The trial judge had been entitled to leave the case to the jury, and her directions on the burden of proof were sufficient. The appellate conclusion did not rest on any error in those directions, but on the safety of the convictions in light of the evidence as a whole.

5. For future cases, where reputable experts seriously disagree after a full investigation and a reasonable possibility of natural causes remains, a prosecution for murder should not ordinarily be started or continued without additional cogent evidence, outside the expert evidence, tending to show that an infant was deliberately harmed. A conviction cannot stand on a high probability of guilt: the court must be sure.

• Court of Appeal (Criminal Division). The appeal against the murder convictions was allowed. The court quashed the convictions on 10 December 2003 and gave its reasons in [2004] EWCA Crim 1.
• Crown Court at Winchester. On 16 April 2002, before Hallett J and a jury, the appellant was convicted of the murders of Jason and Matthew.