The man who opened fire at a Midtown Manhattan office building last month, killing four people and injuring another before fatally turning the gun on himself, had a history of run-ins with police in his hometown of Las Vegas,

Police had twice visited the home of the gunman who killed four people in a Midtown Manhattan skyscraper in recent years over fears he was armed and suicidal, according to criminal records including 911 calls and body-camera footage.