Khan had been previously sentenced to an indefinite period in hospital

Paul Khan, 34, carried out a frenzied knife attack on 72-year-old Brian Dodd, at Ffrith Beach, in Prestatyn, north Wales, in March.

He landed 37 blows on Mr Dodd, a retired accountant described as "a shy and gentle man", mainly in the head and neck.

Khan, of Cardiff, pleaded guilty at Chester Crown Court yesterday to manslaughter on the grounds of diminished responsibility.

His motive remained unclear as he told police he had no memory of the incident.

It emerged that Khan was sentenced to an indefinite hospital order in 1996 after walking into a Cardiff library and slashing a man's throat.

He was treated at various secure hospitals and in 2000 a mental health review tribunal ruled that he could be treated in the community.

Lessons to be learned

On Saturday, a spokeswoman for the Welsh Assembly Government said a review of the incident would take place.

She added: "Last year new policies were implemented following a report by the Health Service Ombudsman. We will look at this case in line with those new policies.

"It is of course important that we learn lessons from this case.

"It has always been the Welsh assembly's position to examine each incident on a case-by-case basis.

"We will review this case and then determine the appropriate course of action."

Khan's sentencing has been adjourned until October 27.

The widow of his victim, campaign group the Zito Trust and mental health charity Sane have demanded a full inquiry into why Paul Khan was released to be treated in the community.

They say Wales needs to follow the English system of having an independent inquiry.

"What I've been led to believe is that this man was let out after he had committed another similar crime," said Enid Dodd.

"The questions I want to ask is why was this man walking the streets? Why was he let out ?

"One of the few things you can honestly say is that this is a crime that could have been prevented."

Enid Dodd wants to know why Khan was let out of hospital

In 1996 Khan was sentenced to be detained in hospital indefinitely after slashing a 31-year-old's face in a Cardiff library.

He spent time at Merseyside's Ashworth secure hospital and the medium secure Caswell Clinic in Bridgend.

He was discharged in 2000 after a mental health review tribunal ruled that he could be treated in the community.

The treatment appeared to work but in March this year Khan stopped taking his medication.

Prevent future tragedies

Then on Tuesday, 25 March, he made the fateful decision to take his dad's Ford Mondeo - with his pet Rotweiller in the back - and drive aimlessly eventually ending up in Prestatyn.

Between 1140 and 1145 GMT he was spotted entering the car park of Ffrith Beach Festival Gardens.

Just over 30 minutes later Mr Dodd's lifeless body was found in the same car park. His two Shitzhu dogs were lying next to him.

A spokesman for Sane said: "We support calls for an independent inquiry into the care and treatment of Paul Kahn.

"Only by doing this will we be able to find out what mistakes were made which left both him and the public at risk, and so we can prevent such tragedies in the future."

Michael Howlett of the Zito Trust, which campaigns for proper treatment of psychiatric patients, said: "The only way to get to the bottom of this tragedy is to hold an independent public inquiry with a published report at the end."