New York City police detectives searched a studio apartment in Las Vegas that belonged to the suspected gunman in Monday's mass shooting at a Midtown Manhattan.

A gunman opened fire in a prominent Manhattan office building on Monday evening, killing four people and seriously injuring a fifth before dying from a self-inflicted gunshot wound, New York City officials said.

On Monday evening, a man armed with an assault rifle walked into an office building in midtown Manhattan and opened fire, killing four people and critically wounding a fifth before killing himself, officials said.