Crown Point, N.Y. ? A man with a rifle killed his girlfriend and a state trooper Monday, then shot himself to death.

Trooper Lawrence Gleason went to the home of Amanda Olcott after she called police and said her ex-boyfriend had threatened her with a knife, police said. While Gleason and Olcott were talking inside, James Scharpf arrived and fired three shots into the mobile home, killing the officer, police said.

Scharpf, 36, then went into the home and killed Olcott, also 36. Then he committed suicide.

Olcott had recently left Scharpf, but he had followed her from Moriah to her new home in Crown Point, about 100 miles north of Albany.

Gleason, 28, had been sworn in as a state trooper last May.

The last time a New York state trooper was killed on the job was in 1994.