Authorities in Arizona say a man arrested in shootings targeting Democratic campaign offices near Phoenix had more than 120 guns and apparently had been plotting a mass casualty event.

An Arizona man who allegedly shot at a Democratic field office in the Phoenix area may have been planning something bigger, authorities say. Federal agents removed more than 120 firearms from Jeffrey Michael Kelly's home after he was arrested Tuesday,

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