A LONELY hearts romeo who slashed his date's throat when she told him she just wanted to be friends has been locked up indefinitely.

Tony Griffin was told he will be freed from a psychiatric hospital only with the approval of the Secretary of State for Justice.

Psychiatrists agreed that Griffin has a sever form of autism, which merited detention in a secure hospital for treatment.

The 20-year-old, from Middlesbrough, became horrifically violent when the young woman tried to end their brief relationship.

Teesside Crown Court heard today how Griffin planned to butcher another woman at the same spot after falling out with her years earlier.

He was found with tape, rope and latex gloves, and admitted he was going to lure her to the remote area to stab her to death.

Judge Simon Bourne-Arton, QC, told him: "You pose a significant danger to the public, in particular young women.

"It is clear you are an exceedingly dangerous young man . . . your previous offending sets out with clarity exactly why."

Griffin's barrister, Mike Bosomworth, told the court that none of the crimes would have been committed had he not had autism.

He said the relationship was Griffin's first, and added: "When he was told it was over, his brain couldn't cope."

Prosecutor Nick Dry told the court that Griffin met the slash victim - around the same age as him - on the dating website, Oasis.

The day after they first met in March this year, the woman told him she did not want a relationship and wanted to be friends.

A week later, they met again because she wanted to explain her decision and walked along the old railway line in Middlesbrough.

Mr Dry said the woman became worried when she saw that Griffin was wearing black gloves - even though it was a sunny day.

He attacked her with a knife, slashing her chest, and was felled as she tried to run away, Mr Dry told Judge Bourne-Arton.

Griffin pulled back her head and made at least seven "methodical slashing movements" at her neck, said the prosecutor.

A dog-walker and another passer-by saw what was happening, intervened and called the police as the woman broke free and fled.

Griffin was said to have been "unemotional" with "a blank expression" before he calmly walked away from the scene.

After his arrest, Griffin said he wanted to "stab her in the back" as he felt he had been when he was rebuffed.

It emerged that he was convicted of harassing and threatening to kill the other young woman in July 2010.

He had plotted to tie up and gag her on the same footpath between Flatts Lane and the Trunk Road in Normanby and stab her to death.

Griffin, of Sandmoor Close, Eston, had been charged with attempted murder and was due to go on trial on September 1.

The trial was abandoned when he pleaded guilty to the lesser charge of wounding with intent to cause grievous bodily harm.

Judge Bourne-Arton told him: "You carried out a brutal, unprovoked, prolonged and, indeed, vicious attack on an entirely innocent young woman, and a highly unsuspecting young woman.

"She had shown you nothing but friendship.

"What was precisely in your mind at the time you attacked her, perhaps nobody, not even you, knows. The very least you intended was to cause her really serious harm."

Griffin, who appeared in the dock wearing a three-piece grey suit and tie, was flanked by two hospital workers.

Mr Bosomworth said: "He understands it will be many years before he is able to be released into the community.

"Obviously, the court will be concerned about his relationships with women. He poses a considerable risk to them because he has an inability to form relationships and to understand the nuances of them."