Psychopath freed to kill after attack

Colin Welsh, 42, beat his first victim so badly that he was left needing facial reconstruction surgery, the Old Bailey was told.

But he was simply fined and sent down from St Andrews University before returning to London. Welsh was left free to stab cabinet maker Elliot Guy, 27, in the neck, severing his jugular vein, at a party in July 2008.

Mr Guy had become a father just 12 weeks before.

His partner, Amy Smith, described him as a "wonderful, warm, gentle and paternal man" who doted on daughter Eleanor.

Jonathan Laidlaw QC, prosecuting, said others described him as "polite and thoroughly decent".

Welsh, who studied philosophy at St Andrews, appeared to be "a normal person who is educated and articulate". But he was a schizophrenic who heard voices he believed were coming from a device placed in his ear.

Welsh, of Tottenham, north London, pleaded guilty at an earlier hearing to manslaughter by diminished responsibility.

Judge Brian Barker, the Common Serjeant of London, adjourned sentencing until today to decide whether to order him to be locked up in a mental hospital.

The court heard that while at St Andrews, Welsh's behaviour was "erratic and at times dangerous".

Other students witnessed "extreme losses of temper and very frightening and intimidating behaviour", said Mr Laidlaw.

He attacked a student in 2006 and in court it was revealed he had dozens of convictions involving drugs and violence. He was fined 200 and ordered to pay 300 compensation.