Crazed Robert Murphy held the weapon to his 71-year-old aunt's back and chest and brandished the knife at a brave neighbour who tried to help her.

During the siege in Evelyn Burns' front garden, Murphy, 43, also threatened to kill his mother Kathleen, after he had been refused entry to the house where they lived earlier that day.

A judge said he must serve at least three years in prison because he poses a real danger to his family.

Teesside Crown Court heard how Murphy frogmarched Mrs Burns from Cameron Road to her home in Lansbury Grove, Hartlepool, as she walked home from a post office on June 23.

He also threatened to kill neighbour Raymond Skelton, who went to Mrs Burns' aid and tried to tackle Murphy with a crowbar.

Patricia Mancina, prosecuting, said: "The defendant marched Evelyn to the front door, she was terrified and screaming.

"He had a crazed look in his eyes and was out of control."

The court heard how Mrs Burns and her two sisters had previously moved away because of Murphy's violent outbursts towards them and had got an injunction to try and keep him away.

During the ordeal, he also dragged Mrs Burns, who suffered a small cut to her hand during the incident, to the living room window and tried to smash it with his elbow.

He continued to make threats – even after armed police arrived – before he was eventually arrested.

The court heard how while in the police van he said: "I will go back and kill them all. I cannot live on my own."

Murphy, of no fixed address, pleaded guilty to charges of false imprisonment, threats to kill against Mrs Burns and Mr Skelton and possession of an offensive weapon at an earlier hearing.

John Ellwood, mitigating, said: "While the incident obviously was very serious and very distressing for everyone and he was making comments which were quite disturbing, he had room to carry out a much more serious offence if he had chosen."

He added Murphy had now come to terms with his family's stance.

Judge Peter Bowers said: "It is quite clear this terrifying incident was pre-meditated in the sense you armed yourself with a knife and expressed over a long period of time the intention of killing your mother and put your aunt through an ordeal which can only be described as horrific."