Four people were killed, including an off-duty New York City police officer, when a gunman opened fire in an office tower before fatally shooting himself, officials said.

The gunman, whom police identified as Shane Tamura, 27, of Nevada, was found dead, apparently from a self-inflicted gunshot wound to the chest, on the 33rd floor of 345 Park Avenue. He killed a woman there after killing three people, including a New York City police officer, in the lobby downstairs.