A spurned lover has been jailed for 19 years for stabbing his ex-girlfriend and her 86-year-old fiance to death after trawling the internet for Breaking Bad poison, a court heard.
Paul Mallin, 51, armed himself with a meat cleaver and 10in (25cm) carving knife before attacking great grandfather John Down and Karen Reid, 53, at the sheltered housing complex where they all lived.
He admitted carrying out the killings on September 5 last year and appeared to be sentenced by Judge Richard Marks QC at the Old Bailey.
Outlining the facts, prosecutor Riel Karmy-Jones QC told the Old Bailey that Mallin's relationship with wheelchair-bound Ms Reid, who had a muscle-wasting condition, had ended in February last year and she transferred her affections.
Mr Down, who suffered from a degenerative eye disease, had met Ms Reid after he moved into the sheltered accommodation having broken his hip in a fall.
The couple got engaged and she moved into his flat at Fernways in Ilford, north-east London.
In April, Mallin had argued with Ms Reid and stabbed the wall of Mr Down's flat with a knife after becoming upset about gifts he had bought her in the past.
The following month, the defendant was punched in the face by a member of Ms Reid's family although no charges were brought, the court heard.
Mr Down complained to staff that Mallin had been to his flat when he was not welcome, and during discussions about it, he was spat at by the defendant.
It was later noted on Mallin's tenant record that he appeared to be "bitter" about the relationship.
Just hours before the killing, the defendant became upset in the lounge area. He said: "I want to kill them" after Ms Reid told him she hated him, the court heard.
Later that evening, an agency staff worker found Mr Down's blood-stained door ajar and, looking through the crack, saw Mallin standing over Ms Reid and repeatedly stab her with the carving knife.
She asked him what he was doing, and he replied: "I have stabbed them both."
When police arrived, Mallin was sitting in the office area in blood-soaked trainers and jogging bottoms looking "sweaty and flustered", Ms Karmy-Jones said.
Officers found Mr Down slumped behind his front door with multiple stab wounds to the body, neck and stomach. His dentures were found on the floor beside him. Ms Reid was sitting in an armchair opposite him, also fatally injured.
After Mallin was arrested, police searched his flat and discovered a torn page from a notebook with "Dirty John" written down and then scrawled out.
They found a large amount of pornography and more than 300 internet searches on poison including "Ricin - Breaking Bad" and "So I gotta kill this guy and get away with it".
Mallin, who moved to the unit in Cecil Road after his parents died, denied murder but pleaded guilty to manslaughter, which was accepted by the prosecution in light of reports on his mental state.
The court heard he had never had a job and had suffered from depression, anxiety and schizoid personality disorder.
In victim impact statements, Mr Down's heartbroken daughters described him as a "gentle giant" who always meant to live to 100.
Pamela White said he was contemplating marriage again at the age of 86 but his happiness was "snatched away".
Ms Reid's sister Maxine Orr said she was a "very happy person" who had suffered in later years.
Despite that, she said: "In John I feel she finally found someone who really loved her and looked after her."
In mitigation, Sallie Bennett-Jenkins QC said Mallin was full of remorse and had remarked: "It's terrible, terrible. This is not me."