Arizona investigators surveilling the man accused of shooting at the Democratic National Committee office in a suburb of Phoenix saw him posting political signs with bags of a white, powdery substance attached,

An Arizona prosecutor said the man arrested in the shooting of a Democratic National Committee office in suburban Phoenix had more than 120 guns and over 250,000 rounds of ammunition in his home, leading law enforcement to believe he may have been planning a mass casualty event.

Jeffrey Michael Kelly, 60, was also arrested on suspicion of leaving white powder on political signs in Ahwatukee, according to Tempe police.

Jeffrey Michael Kelly, 60, allegedly fired gunshots at the glass front door and a window of an Arizona Democrats' field office.

Police investigating a series of shootings a Democratic National Committee office in Arizona found more than 120 guns, 250,000 rounds of ammunition and a grenade launcher at the home of a suspect, according to the local attorney’s office.

Officials seize more than 200 guns from home of Arizona man arrested in Democratic office shooting.

Authorities said they found 120 guns and 250,000 rounds of ammunition when they raided Jeffrey Kelly's Arizona home.

The man arrested in connection to a shooting at the Democratic National Committee’s (DNC) field office in Tempe, Ariz. may have been planning a mass casualty event, Maricopa County prosecutor Neha Bhatia said in court on Wednesday,

A suspect has been arrested in connection to three separate shooting attacks on a Democratic National Committee office in Arizona, the Tempe Police Department said.