New York police said Jerome Isaac, the man arrested this weekend in connection with burning to death a 73-year-old woman in Brooklyn, may have been motivated to commit the crime because of an alleged $2,000 unpaid debt.

Earlier reports identified the victim's name as Doris.

Gillespie was burnt to death shortly after 4 p.m. on Saturday inside an elevator of the Prospect Heights building she lived in. The incident as caught on video cameras.

New York Police spokesman Paul Browne told the media that Isaac walked into a police station overnight, smelling of gasoline, and implicated himself in the killing.

Isaac is now facing murder and arson charges and is expected to go before the court on Monday.

Authorities told The Associated Press that Isaac, of Brooklyn, set Gillespie on fire because she owed him $2,000 for work he had completed for her.

Browne said that the woman was sprayed with flammable liquid before she was set ablaze. Gillespie was carrying grocery bags at the time of the attack. She tried to protect herself from the liquid, but the man doused her head, arms and parts of her body, before lighting her on fire with a Molotov cocktail.

This was a methodical attack on a defenseless 73-year-old woman, Browne said, as reported by the Los Angeles Times. It's as bad as it gets.

Neighbors reported the fire but had no idea that a woman was being burnt. The six-story building was evacuated.

Browne told The AP that Isaac set Gillespie on fire he also lit another fire at his own apartment building close by. Isaac then reportedly hid on a roof before going to police to turn himself in.

The Los Angeles Times has reported that Gillespie's nephew, Rickey Causey, has denied that his aunt owed Isaac money.