An elderly man stabbed his girlfriend more than 70 times in a ‘drug-fuelled psychotic rage’, before sitting down to watch television next to her dead body.
Donald Payne, 64, killed Simone Ambler, 49, in Blackpool, Lancashire, in March last year.
He had become paranoid the mum-of-two was ‘putting stuff into his tea.’
He later told police the pair had argued over drugs and she had ‘been getting on my nerves.’
At Preston Crown Court this week Paul Cummings, prosecuting, said: ‘The victim had received multiple wounds all over her body.
‘The effect of that was that sadly, despite the presence of a number of paramedics, a decision was taken fairly soon that Ms Ambler had died.’
The 49-year-old was found with 70 knife injuries, which all stemmed from a 13cm pronged blade found at the scene.
She had been stabbed in her neck, the chest, the abdomen and across her legs and arms, the court was told.
Payne was charged with murder and pleaded guilty to the lesser charge of manslaughter in November last year.
On Friday, he was sentenced to 18 years in prison.
Judge Simon Medland had been told Payne had been suffering from an undiagnosed psychotic illness at the time of the attack.
He was said to have been a long-time user of heroin, crack cocaine, spice and alcohol.
His daughter Emily Payne told the court: ‘My dad did not trust authority figures.
‘He was adamant they were after him and he mentioned that Simone was putting stuff into his tea and indicated that she was working for them.’
Payne’s defence team argued his undiagnosed condition impacted his ability to act rationally, and Ms Ambler’s death demonstrated an ‘utter loss of self-control’.
He was said to be ‘incredibly sorry’ and ‘shocked’ about the violent murder.
But Judge Medland ruled Payne still posed a serious risk to the public, particularly women.
He had 49 previous convictions, including an eight year prison sentence for grievous bodily harm in 1991.
Judge Medland said: ‘The manner of this killing was a dreadfully appalling attack with a knife.
‘There are 70-odd stab wounds on the victim and they would have required considerable force to inflict.
‘You have continued to use drugs over many years, including spice… the outcome is you carried out a dreadful attack on your female partner.
‘This was during a psychotic episode, but a psychotic episode which was, in part, caused by your voluntary use of substances which had greatly unbalanced your mental stability.’
Payne was given a life sentence, reduced to 18 years due to his guilty plea.
He must serve a minimum of 12 years, minus the 435 days he has already spent in custody, before he is considered for release.