Steve Bouquet, 54, stabbed at least 16 pet cats between October 2018 and June 2019 in central Brighton – and potentially many more, a court heard.
He killed nine cats and seven more he left for dead survived.
Bouquet could be responsible for other possible cat attacks in the city, Lewes Crown Court in Chichester heard.
The former shopping centre security guard was tried in his absence after failing to appear at court for his trial.
Police apprehended him in Brighton on Monday night after a tip off from a member of the public who saw him drinking and behaving oddly in a city park.
His location was kept secret from the jury who took three hours to find him guilty today.
Bouquet will be arrested when doctors have finished assessing his physical and mental state.
Lewes Crown Court in Chichester heard Bouquet had pictures of the cats he attacked on his phone.
When they searched his flat, police found a knife stained with feline blood in his kitchen.
Phone data placed him at or near the scene when cats were attacked.
Bouquet obsessively searched online for coverage of his animal cruelty, the court heard.
He copied reports from Brighton daily paper The Argus and The Guardian onto his phone as news of his crimes spread.
Bouquet was convicted of damaging and destroying property and could be jailed.
His Honour Judge Jeremy Gold QC described the attacks as ‘very unpleasant’ and said they had ‘a significant impact’ on the owners who relied on their cats for companionship and comfort.
“The very thought of having a knife plunged into their beloved pet is a serious matter,” the judge said. “I take a very serious view of this case.
“There will be consequences.”
Police were baffled and ‘The Brighton Cat Killer’ was an invisible man until he was revealed by a single error, the court heard.
Rowan Jenkins for the prosecution said: “Great care was taken by Mr Bouquet to be and remain the invisible man.
“There were no clues left at all and nobody witnessed the attacks, which often happened after the hours of darkness.
“But on May 31, 2019, he made a mistake.
“He made a single mistake but that was all that was needed to expose him.”
A camera fixed to the outside of the house where another victim lived picked up a man attacking a cat called Hendrix.
Mr Jenkins said: “In the early evening of 31st May 2019 Stewart Montgomery and his partner Agatha Altwegg were at home in Brighton.
“At around 7.50pm their nine month old black shorthair with white chest patch called Hendrix, came running in.
“At first Miss Altweg thought nothing of it, but she then saw blood where he had been sitting and when looked closer found he was bleeding heavily.”
Hendrix could not be save and the vet who treated him said she had never seen a case like it, Mr Jenkins said.
“In her opinion, this was, in fact, a single wound with a blade penetrating from the left side through to the right - driven straight through.”
Neighbours who had installed CCTV after their own cat was attacked found footage of a Mr Bouquet stroking Hendrix.
Mr Jenkins said: “He appears to show affection to the cat by stroking it.
“Facing sideways, he seems to take something from his rucksack.
“As the cat lies down in front of him, you will see there is then a sudden jerk from the defendant’s arm.
“This, is the moment we say when the defendant stabs Hendrix with some force. Immediately, he reacts by getting to his feet and fleeing to his home.
“The defendant is seen to rearrange his rucksack and continues to walk North.”
The nine pets who died following the attacks were Hannah, Tommy, Alan, Nancy, Gizmo, Kyo, Ollie, Hendrix and Cosmo.
Another seven animals survived – Wheatley, Alistair, Rigby, Gideon, Samson, Jasper and Maggie survived.
Vet bills for some owners ran into thousands, the court heard.
“Despite their best efforts, many of the animals could not be saved,” Mr Jenkins said.
Bouquet, from Brighton, will be sentenced later.