Walter Edward Stolper was facing eviction and stewing with anger at his Jewish neighbors in Miami Beach when he threatened to take revenge, the authorities said on Friday.

Mr. Stolper, 72, told a business associate that he planned to set fire to his condominium building and “kill all Jews” inside, the Miami Beach Police Department said.

He was well on his way to carrying out that plan when the police arrived on Thursday, finding him in a parking garage with two gasoline containers, according to a police report. The police said Mr. Stolper had already poured gasoline down the condominium building’s trash chute, and had 28 more gasoline containers and explosive materials in his storage unit.

Mr. Stolper could have caused an explosion at the building, which has about 400 units, “within minutes,” said Officer Ernesto Rodriguez, a spokesman for the Police Department.