A convicted arsonist was arrested on charges alleging he kidnapped and raped a 50-year-old Roman Catholic nun the day after he was released from jail, authorities said.

Leroy Racklin, 31, was arrested Thursday on charges of rape, assault, kidnapping, carjacking and crack cocaine possession.

Police say Racklin carjacked the nun Tuesday night, raped her and held her captive for eight hours before releasing her. A few hours later, he drove her car to a police station and told officers he was trying to return it to its owner, police said.

In a jailhouse interview with the San Francisco Chronicle, Racklin denied raping the woman and said he did not know she was a nun.

He said she had driven him to a San Francisco hospital where he was visiting a relative who had been shot. She then lent him the car, but disappeared from the hospital a short time later, Racklin said.

"Everybody at the hospital saw me with this lady," he said. "I don't rape females; I sure as hell don't carjack them."

Racklin served time in state prison for trying to burn down a building where his girlfriend lived, authorities said. He was arrested two weeks ago for failing to register as an arsonist and was released Monday on probation, authorities said.