BROOKLYN - A Brooklyn man will spend at least 50 years in prison for the brutal murder of Deloris Gillespie.

Jerome Isaac, 48, pleaded guilty to first-degree murder, arson and torture. Investigators say he stalked Gillespie, waiting for the right time to strike. He caught her while she was on an elevator, where he poured gasoline on her and set her on fire.

The attack was caught on surveillance cameras.

Prosecutors say Gillespie was trying to be a Good Samaritan by hiring Isaac and letting him stay with her while he fixed her plumbing. They say Isaac attacked her because he felt she owed him money for plumbing work.

Isaac will be sentenced this afternoon.