A man with self-described mental health problems was ordered held without bail in Florida on Thursday on charges that he had threatened to assassinate Democratic presidential candidate Barack Obama or President George W. Bush. Raymond Hunter Geisel was arrested by the Secret Service in Miami on Saturday after making threats before other participants against both Bush and Obama at a bail bondsman's training course, according to federal court papers.

A Secret Service affidavit said Geisel denied making the threats. But he told a Secret Service agent, in comments he later described a joke, that if he wanted to kill Obama he would simply shoot him with a sniper rifle.

An unidentified female witness told investigators that Geisel had said during the course between July 25-28, "That n----r, if he gets elected, I'll assassinate him myself." Obama would be the first black U.S. president if elected.

Another witness was said to have overheard Geisel say at a hotel that he hated Bush and wanted to put a bullet in his head.

Police found an ample cache of ammunition, including armor piercing bullets, and a handgun in Geisel's sport utility vehicle and the Miami hotel room where he was staying while attending the bail bondsman's course. It is legal to possess armor-piercing bullets in Florida.

Secret Service spokesman Ed Donovan said the agency would not comment on the number of threats to government officials or political candidates detected at any given time, but that this "might be the first arrest" in connection with the current presidential campaign.

Court documents said Geisel, a long-term resident of Bangor, Maine, had described himself as a victim of physical and emotional abuse when he was younger and said he had voluntarily checked himself into a mental health facility in Maine for treatment of post traumatic stress disorder.

A bail bondsman pledges money or property as a guarantee that an accused criminal will appear in court.

(Reporting by Tom Brown, Editing by Michael Christie and Patricia Zengerle)