A man is being held in Florida by federal authorities on charges of threatening to assassinate Democratic presidential candidate Barack Obama. Raymond Hunter Geisel was ordered held without bail Thursday at a brief court hearing. The Secret Service says Geisel made the threat during a training class for bail bondsmen in Miami in late July. Another tipster said Geisel also threatened President George W. Bush. A search of Geisel's SUV and hotel room uncovered a loaded handgun, knives, dozens of rounds of ammunition, body armor and a machete. The SUV was wired with emergency lights.