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.

In the aftermath of New York’s deadliest mass shooting since 2000, authorities are investigating the motives and background of the man who opened fire in a midtown Manhattan office skyscraper, killing four people and then himself.

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,