It could be possible in future to use a person's genes as a mitigating factor in a court of law, according to the Nuffield Council on Bioethics working party's report on the impact of our genes on our behaviour.
Genetics and Human Behaviour: The Ethical Context says that rather than absolving the individual from responsibility for an offence, a judge could be asked to take genetic predisposition to criminal behaviour into account in the same way asenvironmental factors such as an abusive childhood or poverty.