Federal authorities arrested a 27-year-old accused white supremacist who allegedly planned to bomb a synagogue in Colorado over the weekend. Richard Holzer had brought a knife and a mask to a motel room and was examining inert pipe bombs prepared by undercover agents moments before he was arrested late Friday night, according to a criminal complaint. He also said he paid a "witch doctor" $70 to put arsenic in the water pipes of the synagogue and "hex" the place last year, according to the complaint.