The New York City office building that was the site of a mass shooting Monday had significant security measures in place.

Four people were killed and a fifth was injured in a mass shooting at a Midtown Manhattan office building on Monday.The injured victim was an employee at the NFL, according to NFL Commissioner Roger Goodell.

The four victims who were shot and killed by a gunman inside a Midtown Manhattan office building on Monday night have been identified.They include two women — a Blackstone executive and a Cornell graduate — and two security guards,

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.