Ram Singh, key accused in the December 16, 2012 gang-rape who allegedly committed suicide in Tihar Jail Monday, was quarrelsome and showed signs of rage when drunk, his neighbours in a slum in New Dehi told an official.
Neighbours of Ram Singh, 35, at Ravidas Colony in south Delhi, described him as "often-drunk", an official said, on condition of anonymity.
"Ram Singh quarrelled and had run-ins with his employers. When drunk he would show rage and pick up fights with people," said the official.
A police investigation following his arrest revealed that the accused, who drove the bus in which the gang-rape took place, had a history of bad behaviour.
Ram Singh's friends used to call him "mental", alluding, perhaps, to his alleged abnormal behaviour, police said.
"Of his four brothers, three had left the family home reportedly because he ill-treated them," said the official.
Ram Singh migrated from Rajasthan to the capital with his family to earn a livelihood.
He was the oldest among the six accused in the gang-rape.
At the time of his arrest December 17, 2012, Ram Singh had been living in a one-room tenement with his younger brother, Mukesh, who is also one of the six accused.
He faced 13 criminal charges, including murder, police said.
In 2009, Ram Singh, son of Mange Ram, had a serious accident while driving a bus in south Delhi and an iron rod had to be inserted in his left arm, leaving it deformed, police said.
Police said that the injury made Ram Singh even more bitter and violent. His wife's death three years ago added to the rage, they said.
Ram Singh reportedly committed suicide in the Tihar Jail in the morning. His family alleged he was murdered.