U.S. judge declares mistrial in Clemens perjury case

Former Major League Baseball pitcher Roger Clemens (front) leaves the federal courthouse in Washington July 14, 2011.

WASHINGTON (Reuters) - A judge declared a mistrial on Thursday in the perjury trial of baseball great Roger Clemens, because prosecutors violated an order that barred certain information from being introduced to the jury.

Judge Reggie Walton was furious at prosecutor Steven Durham for introducing evidence that appeared to bolster the credibility of a future witness, Clemens' former teammate Andy Pettitte, and referred to Pettitte's wife, Laura, after the judge issued an order that limited or barred such information.

"A first year law student would know that you can't bolster the credibility of one witness with clearly inadmissible evidence," Walton said, raising his voice in anger at Durham. "I don't see how I unring the bell."

The mistrial was a major setback for the government, which spent a year preparing the case. Four days were spent on selecting a jury.

Walton said the parties would have to discuss whether retrying Clemens would violate the constitutional protection against double jeopardy, which protects an individual from being tried twice for the same offenses.

A hearing on the double-jeopardy issue will be on Sept. 2 but no new possible trial date was set.

Durham had pressed Walton to instead instruct the jury to disregard the information which was presented in a video of the 2008 congressional testimony by Clemens to the House of Representatives Committee on Oversight and Government Reform.

"I'm not going to put this man's liberty in jeopardy," Walton said, adding that prosecutors could not persuade him to reconsider his decision. "You're not going to be able to convince me."

Clemens is facing charges that he lied to the committee when he denied taking steroids and human growth hormones from 1998 to 2001. The pitching star and one-time Hall of Fame contender has denied taking drugs or lying to Congress.

In admonishing the prosecutor, Walton said Durham had violated his order during his opening statement as well. The judge also said that defense lawyers should have raised objections immediately when the information was played.

The video showed Democratic Representative Elijah Cummings making references during the 2008 hearing about Pettitte, who admitted to using steroids, and conversations Pettitte said he had with his wife about Clemens talking about using human growth hormones.

Clemens has said that Pettitte, a onetime close friend, had misremembered and misheard the conversation which had been relayed to his wife Laura. Walton had previously excluded any initial references to Laura Pettitte.

Clemens, 48, pitched for four teams during his 24-year career in baseball, including the New York Yankees, Boston Red Sox, Toronto Blue Jays and Houston Astros. He was one of only four pitchers to strike out more than 4,000 batters.

He was a seven-time winner of the Cy Young Award annually honoring the best pitcher in each league.

(Reporting by Jeremy Pelofsky in Washington; editing by Mohammad Zargham)