Khan had been previously sentened to an indefinite period in hospital

On Friday Chester Crown Court heard how the knife attack on 72-year-old Brian Dodd as he strolled along Ffrith beach in Prestatyn, was described today as "motiveless, random and bizarre".

The retired accountant was stabbed more than 10 times with a seven-inch carving knife.

His widow, campaign group the Zito Trust and mental health charity Sane are demanding 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 has committed another similar crime," said Enid Dodd.

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

Diagnosed as a paranoid schizophrenic, Khan, from the Tremorfa area of Cardiff, pleaded guilty to manslaughter on the grounds of diminished responsibility during a 20-minute hearing. Sentence has been adjourned until 27 October.

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.

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

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 Zito Trust's Michael Howlett

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 liefless body was found in the same car park. His two Shitzhu dogs were lying next to him.

As there were no witness accounts, is is unknown if Khan was also walking his dog on Ffrith Beach and had come into contact because of their dogs.

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.

"We have had about 150 similar inquiries in England in the last 10 years but they have never had one like it in Wales."

A spokesman for the Welsh assembly said: "We will be reviewing this case and will then decide on the appropriate course of action."