A mentally ill homeless man will serve 57 months in federal prison for threats he made against President Bush.

Timothy Wade Pinkston threatened in August to go to Washington and shoot Bush. At the time, the 48-year-old was committed to a hospital psychiatric unit.

Court records say he repeated the threat to Secret Service agents, saying he didn't like the president's foreign policy or his handling of the war in Iraq.

Pinkston told a federal judge in Tampa on Wednesday that he is HIV-positive and bipolar and has a substance abuse problem. He said he'd been taking drugs and drinking when he made the threat and didn't know what he was saying.

He was previously charged with threatening the president in 1991 and also sent threatening letters to the governor of Georgia.