A thug was caught on camera murdering his step-father in a horror hammer attack.
Dean Martin brutally killed Keith Allan having blamed the 42 year-old for his mother's earlier death.
The 33 year-old struck last July 5 at the house they shared in Bathgate, West Lothian as two children cowered upstairs.
The attack spilled outside as blood-soaked Keith desperately yelled for neighbours to help him.
A judge heard how one woman captured part of the incident on her mobile phone as Martin continued the assault on the doorstep.
The delivery firm worker now faces a life sentence after he pled guilty to a murder charge at the High Court in Glasgow today.
Keith had been married to Martin's mum Christina Allan for 16 years.
But, she tragically took her own life last June 9 - just weeks before the killing.
Prosecutor Mark Mohammed said Martin "formed the belief" that Keith was responsible for what happened.
Despite that, on July 1, Martin moved in with Keith having split from his partner.
But, the hearing was told they went on to "argue frequently".
On the afternoon of the murder, Keith told a woman he was "struggling" with Martin living at the house.
However, he decided to give his step-son "one more night".
Just hours later, Martin went on to kill Keith striking him at least 15 times with a hammer.
Two children upstairs had initially been alerted to Keith shouting: "What are you doing to me?"
Martin screamed back: "You should not have done that to my mum."
One of the children was described as "hyperventilating" as he phoned for help.
Keith managed to crawl to the front door despite being under attack.
One neighbour then tried to step in.
But, Mr Mohammed told the hearing: "Keith Allan repeatedly shouted 'help me'.
"Martin shouted to the man: 'It is ok. It has got nothing to do with you'."
A retired police officer also tried to intervene. He spotted Keith lying "half in and half out" the front door covered in blood.
The mobile phone clip was played today/yesterday. Martin refused to look at the screen and sat with his head in his hands in the dock.
Martin called his ex-partner after the killing stating: "I've just done him. I'm really sorry.
"My mum told me to do it. He killed my mother."
Keith did not survive the attack having suffered "extensive head injuries".
A claw hammer was found by police hanging from a fence at the front door.
After being held, Martin again apologised for what happened.
The court was told Martin claimed his mum had been given drugs by Keith.
But, it was stated there was "no evidence" drug use was linked to her death.
Lord Matthews remanded Martin in custody and deferred the case for reports.
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