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 who killed four people at a Manhattan office building bought the rifle from his supervisor at a Las Vegas casino, authorities said.

Authorities confiscated several items from a Las Vegas apartment tied to a gunman who used an AR-15-style rifle to kill four people in Manhattan, according to records made public Friday.