TEMPE, Ariz. — A 60-year-old man suspected of shooting at a Democratic National Committee office over the last two months and hanging suspicious bags of white powder from political signs in a nearby village had over 120 guns and over 250,000 rounds of ammunition in his home and was preparing for a "mass casualty" act, according to prosecutors.

An Arizona prosecutor said the man arrested in the three-time shooting of a Democratic National Committee office in suburban Phoenix had more than 200 guns and over 250,000 rounds of ammunition in his home,

The suspect also allegedly hung suspicious bags of white powder from political signs in a nearby village, police say.