Keoghs Insight


Ian Carroll

Abuse and the illegality defence: Supreme Court guidance


Civil claims for abuse often include attempts to claim for losses flowing from criminal behaviour, most commonly drug use, which is alleged to have occurred as a result of the abuse they suffered. In this respect, the established law from the House of Lords decision in Gray v Thames Trains Ltd in 2009 has always made it clear that under the defence of illegality (“ex turpi causa”) a claimant is not entitled to recover any damages for the consequences of their criminal behaviour, including the illegal use of drugs, even if it is found that they would not have engaged in such criminal behaviour but for the alleged abuse.This has been considered by the Supreme Court in Ecila Henderson v. Dorset Healthcare University NHS Trust Foundation [2020] UKSC 43 where it revisited the defence of illegality.


Ms Henderson suffered from paranoid schizophrenia or schizophrenic disorder and was under the care of the local community mental health team.  Whilst experiencing a psychotic episode she stabbed her mother to death and was subsequently convicted of manslaughter on the grounds of diminished responsibility.  Ms Henderson then pursued a civil claim against the local Trust for failing to return her to hospital when her condition deteriorated which, had they done so, would have prevented her from killing her mother. Liability was admitted but the Trust argued that her claim could not succeed on the basis of illegality in that her losses resulted from her own criminal act.

The Supreme Court agreed with the Trust and expressly reiterated that Gray v Thames Trains remained good law. The facts of that case were broadly similar where a train passenger suffered PTSD as a result of being involved in the Ladbroke Grove train crash and later went on to stab a pedestrian to death who stepped in front of his car. Mr Gray was convicted of manslaughter on the grounds of diminished responsibility and unsuccessfully pursued a civil claim against Thames Trains who relied on the defence of ex turpi.In Henderson, the Supreme Court reiterated there were important public policy considerations as to why the ex turpi defence in Gray v Thames Trains was justified:

  1. Consistency between criminal and civil law: it would be inconsistent to imprison a person for the consequences of their criminality but then compensate them for it, or as Lord Sumption put it in the case of Patel, “condone when facing right what it condemns when facing left”; and
  2. Maintaining public confidence in the legal system: allowing a claimant to be compensated for the consequences of their own criminal conduct risks bringing the law into disrepute and diminishing respect for it.


Criminal behaviour is not the inevitable outcome for victims of abuse. However, there is no doubt that individuals who have been sexually abused are at an increased risk of going on to have an involvement in criminal behaviour in adult life. This case therefore provides helpful guidance with regards to attempts in civil claims to recover damages arising from a claimant’s subsequent criminal behaviour.

For more information, please contact Partner, Ian Carroll.