The funeral will be held Thursday for the police officer who was one of four people killed in Monday's mass shooting at a Midtown Manhattan office building.

The attacker reportedly drove cross-country from Las Vegas to New York in the days leading up to the shooting.

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

Shane Tamura, 27, who police said fatally shot four people Monday in the midtown skyscraper that houses the National Football League's headquarters, said in a suicide note that he believed he had chronic traumatic encephalopathy,