Can Arslan, 52, was facing eviction proceedings and a harassment charge when he attacked Matthew Boorman outside his Gloucestershire home last October.
Mr Boorman was on a work conference call when he was stabbed 27 times.
When Mr Boorman’s wife Sarah tried to save her husband, she was stabbed in the thigh.
Arslan then forced his way into the rear garden of other neighbour, Peter Marsden, and stabbed him eight times.
An off-duty policeman, Sergeant Steve Wilkinson, then chased down Arslan and hit him with a piece of wood.
Arslan was then surrounded by a group of men in the street to try and stop him from hurting anyone else.
He only dropped the knife when he was “red-dotted with a Taser”.
As Arslan was arrested, he gloated about what he did to police.
“He’s dead, isn’t he? I warn you, the police,” he said.
“I warned them I was going to murder him.”
Detective Inspector Ben Lavender said Mr Boorman’s children were only “a few feet away” at the time of the murder.
“The events which unfolded on that early evening in October last year were truly horrific, and Arslan has not shown a single shred of remorse for his barbaric actions,” Detective Inspector Lavender said.
“He carried out an inhumane act in broad daylight on the front lawn of Matthew Boorman’s home, while his incredibly brave wife and neighbours did everything they could to try and save him.”
Arslan’s defence team argued that he was suffering from an “abnormality of mental function”.
But the jury rejected the claims of diminished responsibility and found him guilty yesterday.
Speaking after Arslan was found guilty, Ms Boorman decried police for their inaction leading up to the murder.
“The police and other authorities had been told about how dangerous this man was, the threats he made, and the risks he presented,” she said.
“The response was toothless and ineffective, even when the defendant himself told the police he was going to murder Matthew.
“That conversation took place on … the night before Matthew died.
“He was not even warned.”
Arslan is due to be sentenced on June 9.
He had previously admitted to the attempted murder of Mr Marsden and the grievous bodily harm of Ms Boorman.