Convicted killer executed with pet anaesthetic

The state of Ohio yesterday executed a convicted murderer using the first lethal injection to contain just a single poison rather than the cocktail of three chemicals that has hitherto been used across the US.

Officials at the state prison in Lucasville confirmed that Kenneth Biros had been pronounced dead at 11.47am local time, not quite three-quarters of an hour after he had been taken from his adjacent cell and led into the death chamber.

He was killed by way of an enormous overdose of the anaesthetic thiopental sodium, which is more commonly used to euthanise pets.

The three-drug cocktail for intravenous injections remains the preferred means of execution in 37 US states. The authorities in Ohio argued, however, that the single drug option would be easier to administer. Critics insisted that the state was essentially putting Biros "to sleep" like a dog and was the victim of human experimentation.

Biros was convicted in 1991 of murdering Tami Engstrom, a young woman he picked up in his car. After killing her, he chopped her up into small pieces. and deposited parts of her across two different states.