Police executed a search warrant at the Las Vegas apartment of Shane Tamura, where the items obtained included a goodbye note and a bipod for a rifle.

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.

The man who stormed a Manhattan office tower with a gun, killing four people before killing himself, worked in the surveillance department of a Las Vegas casino, part of an industry built on watching for threats before they unfold.