A FREED double killer is behind bars again for launching a crazed “Hannibal Lecter-style” attack on his ex’s lover when he caught them together in a flat.

Vicious thug Allan Shreenan stabbed Robert McKenna to death in Cardross in 1999 - seven years after killing Sean Gillespie in Bonhill.

And the 47-year-old is now facing another lengthy jail term for a brutal attack after breaking into his victim’s Clydebank home and attacking him on August 24 last year.

Shreenan, from Dumbarton, bit the man’s ear during the savage assault, the court heard.

The 29-year-old victim, was sitting in his ground-floor flat in Flanders Street on the evening in question when Shreenan’s ex-girlfriend came to see him.

Shreenan, who claimed they were still together, suspected she was seeing someone else and went looking for her.

He crashed through the victim’s door “like a steam train” – and caught his former partner on her knees in front of the victim, who was in a state of undress.

Shreenan knocked the woman to the ground and launched his attack on the victim.

But he denied his guilt over the incident and went on trial at Dumbarton Sheriff Court last week.

His victim told the court he and the woman were getting intimate when Shreenan burst into his home, breaking the door frame as he entered.

He explained: “As far as I knew, as far as anyone else knew, she was single. He came through my door and attacked me. Joiners had to replace the whole door frame. I had never seen him before and never heard of him.

“I don’t know how he even knew where I stayed.

“My trousers were open and he was standing to attention.

“I remember her shoe fell off during the incident in the bedroom.

“I had to fix myself when the door crashed in.”

The victim panicked when he was attacked but managed to get the better of Shreenan and knocked him out.

He explained: “I definitely didn’t know who it was and definitely did panic.

“He jumped on top of me, grabbed me and started punching me about.

“I didn’t get the better of him until about a minute into it.

“I got him in a choke hold.

“He comes into my house and gets choked out – you’re a big hard man, aint ye?

“I didn’t even get to swing a punch.

“The one time I did I stopped myself and that’s how I got my ear bit.

“I started choking him.

“He stopped his screaming and slevering and wasn’t moving.”

The victim managed to flee from his property and was spotted by a neighbour in the close, bent over, with his hands on his knees, trying to catch his breath.

When Shreenan, who had left his children sitting in his car outside during the attack, regained consciousness he also fled the property, took his children out his car, dumped them at the roadside and sped off.

Giving evidence in his own defence, Shreenan claimed he went looking for his ex as their son needed to go to hospital and thought she was visiting the home of a friend.

Shreenan denied he and the woman had split and described his shock when he discovered the pair within the Faifley home.

He admitted he’d struggled and fought with the victim, punched him repeatedly and bit his ear after entering his home.

But he said he had been provoked and acted in self-defence when the victim and his ex attacked him after he caught them together.

He told the court: “I just thought it was a friend’s house so I was expecting to see a lady, I didn’t expect to see a man that’s for sure.

“I opened the first door I came to and I saw the two of them in a compromising position.”

He added: “It was a bit of a shock as you can imagine. The two of them got up, fixed themselves and tried to attack me.”

Procurator fiscal depute David McDonald asked the jury to convict Shreenan of the “Hannibal Lecter-like” attack.

The prosecutor explained: “[The victim] did his very best to tell you exactly what happened, demonstrating quite vividly the assault that Allan Shreenan subjected him to, right down to the Hannibal Lecter-like noise made by Mr Shreenan as he took (the victim’s) ear in his mouth and bit down on it.”

And they took less than an hour and a half to reject Shreenan’s lies and find him guilty of a charge of hamesucken – breaking in to the complainer’s house and assaulting him.

Shreenan was remanded in custody and will be sentenced next month.

He was jailed for seven years for culpable homicide for killing Mr Gillespie in Bonhill in 1992, stabbing him out of revenge because the 27-year-old had battered him in a street fight.

He was freed from prison early and stabbed Mr McKenna, 36, to death in Cardross in 1999 before fleeing to Ireland.

He was extradited following a BBC Crimewatch appeal and was jailed for 12 years but was released early again, allowing him to attack his ex’s new partner.