Gunman Who Killed 3 U.N.L.V. Faculty Members Wanted College Jobs, Officials Say

The man who shot and killed three faculty members on Wednesday at the University of Nevada, Las Vegas, was himself a professor who had tried and failed to get several jobs at colleges in the state, the authorities said on Thursday.

The gunman, Anthony Polito, 67, was living in a Las Vegas suburb and was killed by the police during a shootout after his rampage, officials said. Mr. Polito also shot and injured a fourth person, a man identified as a 38-year-old visiting professor who was being treated at a hospital for life-threatening wounds.

Shortly before the shooting, the police said, Mr. Polito had mailed 22 letters to employees at universities across the country, at least one of which contained an unknown white powder that was later determined to be harmless. The contents of the additional letters were not clear.