But there are cases where abnormalities in the brain cause criminal behaviour. In 2002, Russell Swerdlow and Jeffrey Burns, neurologists at the University of Virginia medical centre, reported the case of a 40-year-old schoolteacher from Virginia who developed sudden, impulsive paedophilia and was convicted of child molestation. He was signed up for rehabilitation, but was kicked off for propositioning staff. The evening before the man was sentenced, he complained of a headache and being unsteady on his feet. He was taken to hospital, where doctors found an egg-size tumour in his right orbitofr...