Former baseball star Roger Clemens' perjury trial ended in a mistrial on Thursday almost as soon as it began. U.S. District Judge Reggie Walton blamed the mistrial on the prosecution, after they showed the jury evidence that he had already ruled out, a videotaped revelations that a teammate had said he'd told his wife Clemens confessed to using a drug. Walton scolded prosecutors, calling it an error that a "first-year law student" would have known not to make, and he couldn't let the former All-Star pitcher face prison if convicted on such "extremely prejudicial" evidence. Judge Reggie Walton left the question of a new trial up in the air.

Defense attorney Rusty Hardin, who had asked for the mistrial, patted Clemens on the back as the judge announced his decision. As he left the courthouse, Clemens did not comment but accepted hugs from a couple of court workers, shook hands with the security guards and autographed baseballs for fans waiting outside. The quick end on only the second day of testimony was the second mistrial involving a superstar player accused in baseball's steroids scandal. Home run king Barry Bonds was convicted three months ago of obstruction of justice, but a mistrial was called on three more serious false-statements charges after jurors couldn't agree on a verdict.