Bodycam footage shown in court captures the moment Can Arslan, 52, was arrested on suspicion of murdering his neighbour, a father-of-three, in Gloucestershire last year.
The suspect appeared to laugh upon learning his neighbour had died and told police he had warned them a year before that he was planning to kill the victim.
Arslan could be heard saying "mother f***er" as officers restrained him, before warning: "You are next – more people are going to die tonight."
He also bemoaned having to wear handcuffs, as he was being placed inside a police vehicle, blaming his arthritis.
Laughing, the alleged killer said: "He is dead, isn't he? I warned you, the police. One year. Look, it happened."
Can Arslan
Gloucestershire Police
Can Arslan arrest
Gloucestershire Police
He later said: "I warned them I was going to murder him... he was against my son, my wife."
"I told police I was going to murder him – I murdered him," Arslan repeated.
Arslan, who is a Turkish national, is standing trial at Bristol Crown Court accused of murdering Matthew Boorman.
Mr Boorman had 27 stab wounds and was attacked on his front lawn.
Arslan, who was facing eviction from his home at the time of the incident, denies murder on the grounds of diminished responsibility.
He has admitted attempted murder, grievous bodily harm with intent and affray.
Yesterday, footage emerged on Arslan being confronted by an off-duty police officer wielding a piece of wood.
Can Arslan arrest
Gloucestershire Police
Stephen Wilkinson, who was carrying the plank, followed Arslan as he walked towards the rear entrance of neighbour Peter Marsden’s home.
Minutes earlier, Mr Boorman had been fatally stabbed on his front lawn.
Mr Wilkinson tried to make Arslan drop the knife he was holding, telling him: "You stand still, now. Don’t you f****** go down there. Put the f****** knife down now. Put it down."
Arslan forced the gate into Mr Marsden’s garden and the CCTV then showed Mr Marsden wrestling him out of his home – having been stabbed eight times – while Mr Wilkinson hits him with the wood.
Mr Wilkinson could be heard telling Mr Marsden to lock his door, and he left the garden and went back into the street.
Arslan then lit a cigarette and left, where he was again confronted by Mr Wilkinson and other neighbours, now armed with golf clubs.
The footage ended with Mr Wilkinson telling Arslan to put the knife down, and the attacker then walked back towards the Boormans’ home.
The trial continues.