Gray v Thames Trains Ltd [2009] 1 AC 1339

The principle of illegality comes in two forms:

1. In its wider form, one is not entitled to seek compensation for any losses they have incurred as a result of their own criminal actions.

2. In its narrow form, one cannot claim damages for harm that arises from the loss of their freedom, a legally imposed fine, or any other punishment due to their own unlawful conduct.

A collision between a Turbo Train operated by Thames Trains and First Great Western High-Speed Train resulted in 31 fatalities and more than 500 injuries. Mr. Gray, a Turbo Train passenger, experienced depression and post-traumatic stress disorder after the incident.

Subsequently, he was involved in a fatal altercation with a pedestrian and was charged with murder. However, his plea was reduced to manslaughter due to diminished responsibility caused by his mental health condition. He was detained in a hospital after a period in prison.

Mr. Gray later filed a negligence lawsuit against the responsible parties, seeking compensation for loss of earnings, damages related to his detention and conviction, and indemnity against potential claims from the deceased pedestrian's dependents.

The central issue was whether Mr. Gray's claims for loss of earnings and damages were recoverable, considering a possible rule of law based on public policy that restricts compensation for the consequences of one's own criminal actions.

Mr. Gray’s claim was invalid.

This case is notable for its nuanced application of the rule preventing compensation for one's own criminal actions.

It underscores the importance of considering the underlying causes of criminal behavior, especially when mental health issues are involved, and distinguishes cases where third-party negligence plays a substantial role.