An official with knowledge of the investigation told The Associated Press that Prescott phoned in a threat to Pitney Bowes that he was going to "shoot the place up." Investigators say a search of Prescott's home turned up more than 20 guns, including assault rifles and handguns, and more than 400 rounds of ammunition.

The official spoke on condition of anonymity because the investigation is unfolding.

The official says though the suspect referred to himself as "a joker," there is no other known connection to the deadly shooting last week at the Colorado movie theater during the latest Batman movie.