A man has gone on trial in Moscow accused of killing at least 49 people.
Alexander Pichushkin has made a detailed confession
The Russian media has dubbed him the "Bitsevsky Maniac" after the park in southern Moscow where most of the murders were carried out.
The accused man, 33-year-old shop assistant Alexander Pichushkin, sat in a glass cage in court.
Far from denying his crimes, he claims he actually killed 61 people. Many of the victims were elderly men who got drunk with him, investigators say.
He is accused of a 14-year killing spree in southern Moscow, which began in 1992. He was arrested in June 2006.
The victims were drowned in a sewer or bludgeoned to death with a hammer, investigators say.
Many Russians would like to see him executed but, as Russia has suspended the use of death penalty, he faces instead a sentence of life in jail.
Russian press reports say Mr Pichushkin was planning to kill one person for each of the 64 squares on a chessboard.
Given his long confession, it seems certain Mr Pichushkin will be found guilty, the BBC's Rupert Wingfield-Hayes reports from Moscow.
Friends and relatives of some of the victims were in court for his appearance on Thursday.
"I am ready to tear him into pieces," said Nadezhda, a victim's sister, quoted by Reuters news agency. "How is it possible even to think of releasing such people?"
Before the Pichushkin case came to light, Russia's most notorious serial killer in recent times was Andrei Chikatilo, who killed 53 women and children. He was convicted and executed in 1994.