New York City has some of the toughest gun laws in the nation. But Monday’s mass shooting showed their limits, security experts said.

Officials say a man carrying a rifle killed four people at a New York City office tower. The shooting took place Monday afternoon at a midtown Manhattan office building that houses finance companies and the NFL headquarters.

President Donald Trump said on Tuesday that he was briefed on the Monday night mass shooting in New York City, saying his “heart was with” the four people killed. “I trust our Law Enforcement Agencies to get to the bottom of why this crazed lunatic committed such a senseless act of violence,