By Richard Galpin
BBC Moscow correspondent
The Russian man known as the "chessboard killer," Alexander Pichushkin, will be sentenced on Monday after a jury in Moscow found him guilty of killing 48 people and attempting to murder three others.
His mother blamed the killing spree on a childhood bang on the head
During the six-week trial at Moscow City Court Mr Pichushkin confessed to murdering more than 60 people in a killing spree which lasted more than a decade.
If this figure is eventually confirmed by investigators, it would make Pichushkin the deadliest serial killer in Russian history and one of the world's worst.
Prosecutors have called for him to be locked up for the rest of his life, including many years in a solitary cell in a maximum security prison.
In a final statement on Thursday, he told the court that "in my time I alone decided the fate of 60 people", Interfax news agency reported.
"I was judge, prosecutor and executioner," he said.
He rejected the accusation that he had acted with "particular cruelty". "It was a sort of ritual, my style, my handwriting. Neither the prosecutors nor investigators know what we got up to in the woods," he said.
On Wednesday, the court was packed with victims' relatives as well as journalists who had come to listen to the announcement of the jury's decision.
It took the head juror more than an hour to read through what they had decided in each of the 51 charges of either murder or attempted murder.
In each case he pronounced Pichushkin guilty with no leniency to be shown.
What was most striking about the extraordinarily long list of attacks was how they became increasingly brutal.
Pichushkin started off mostly drowning his victims by throwing them into the sewer.
Most of the murders took place in Bittsa Park, southern Moscow
But by 2002 he was shooting them through the head with a home-made gun.
By the end of that year he had moved on to his most gruesome method of killing - attacking his victims with a hammer.
Multiple blows to the head left 14 dead - just one survived.
He did not even bother hiding the bodies.
With some victims he inserted a vodka bottle or stick into their smashed skulls.
He always preyed on the weak, luring the elderly, alcoholics, drug-addicts and even a disabled man into a park in southern Moscow by offering them vodka.
He ensured they were drunk before attacking them knowing they would not be able to put up any resistance.
If Pichushkin had not eventually been caught by the police last year, he says he would have killed many more.
The chessboard reported to have been found in his apartment, on which he recorded all the murders, already had bottle-tops placed on 62 of the 64 squares.
We were uncomfortably close to Pichushkin in the courtroom on Wednesday, but were protected from him by the reinforced glass cage he sat in throughout the trial.
Prosecutors say Pichushkin should serve life in a labour camp
He looked remarkably relaxed when we first arrived, slouched in the corner of the cage, his feet up.
He was dressed casually in black trousers and grey jumper with the sleeves rolled up, revealing powerful forearms.
His pallid face had what seemed like a perpetual frown.
If you caught his eye, he looked back at you and then looked away.
You wondered what appalling and bloody scenes those dark, troubled eyes had witnessed.
During the court hearing prosecutors revealed that Pichushkin had had a history of psychiatric problems in childhood and early adulthood.
But these had apparently faded when he was in his twenties, and all the reports from the supermarket and other businesses which had employed him were very positive.
What turned him into such a brutal murderer is still far from clear.
He himself told the court that his first murder was "like first love, unforgettable".
He then became obsessed with killing, deriving perverse gratification from what he was doing.
As chief prosecutor Yury Syomin told us: "His wish was to kill as many people as possible."
His mother blames it all on an accident he suffered when he was just four years old, when he was hit in the head by a swing.