New York ? A teenager accused of killing his stepfather with a samurai sword denied it Thursday but testified that the retired police officer had molested him for years and had threatened to kill him if he told anyone.

Zachary Gibian, 19, said that he came home the morning of the slaying in 2005 to find his mother covered in blood and his stepfather dead in the living room with a huge gash in his neck.

The teenager claimed that Scott Nager had repeatedly forced him to perform a sex act on him, sometimes with a pistol held to his head, beginning when he was about 15.

Gibian also said that Nager forced him to read pornographic magazines, some of them depicting men having sex with children.

Gibian did not directly blame his mother for the slaying but said she was the only person in the Hauppauge home on the morning the retired 51-year-old New York City police officer was slain.