Man held over Democratic office shootings may have planned ‘act of mass casualty’ The Guardian USArizona Man Is Arrested After Shootings at Democratic Campaign Office The New York TimesFBI finds hundreds of weapons at home of suspect in Arizona Democratic Party office shooting The Arizona RepublicChips & salsa: Arrest made in Dem office shootings AxiosSuspect in shooting incidents at Harris campaign office in Arizona was preparing for a ‘mass casualty’ act, prosecutor says NBC News