In Britain, samples can be taken from, for example, people suspected of driving under the influence of drink.

ECONOMIST: A survey of the human genome

Home Office pathologist Andrew Davidson said Mr Hiles, who was not under the influence of drink or drugs, died of a head injury.

BBC: Jonathan Hiles

He said courts should be able to impose life sentences if there were aggravating circumstances like driving under the influence of drink or drugs.

BBC: NEWS | UK | Longer term for dangerous drivers

The government's anti-drugs co-ordinator, Keith Hellawell, told the BBC he wanted to target young people who, in contrast to drink-drivers, make up the majority of those driving under the influence of drugs.

BBC: You are in: UK