Washington ( CNN ) -- The perjury trial of ex-baseball all-star Roger Clemens ended in a mistrial Thursday after jurors heard statements in a prosecution video that the judge had ruled inadmissible until later in the case . U.S. District Judge Reggie Walton said prosecutors should have modified a video that showed a congressman talking about a deposition from the wife of Clemens ' old teammate , former New York Yankees pitcher Andy Pettitte , during a 2008 congressional hearing . Walton had decided earlier that prosecutors could n't include references to Laura Pettitte 's testimony unless it was brought up on rebuttal . `` I ca n't in good faith leave this case in a situation where a man 's liberty is at risk when the government should have taken steps to ensure that we were not in this situation , '' Walton said after Clemens ' lawyers asked for a mistrial . `` I do n't see how I can unring the bell . '' The decision came on the second day of testimony in the trial . Walton set a September 2 hearing on whether to retry the case . Clemens left the courthouse without comment after the ruling , telling reporters , `` I 'd appreciate it if y'all would let me walk home now . '' Clemens , nicknamed `` Rocket , '' is accused of perjury , obstruction of Congress and making false statements about his alleged use of steroids and human growth hormone . During an appearance before a House committee in 2008 , he testified that he never used illegal performance-enhancing substances during his career -- a statement prosecutors say is contradicted by witnesses and physical evidence . He faced a maximum sentence of 30 years in prison and a $ 1.5 million fine on the counts against him . Clemens was one of the most feared pitchers in all of baseball during 24 seasons playing for the Boston Red Sox , Toronto Blue Jays , Houston Astros and New York Yankees . He retired in 2007 with 4,672 strikeouts , seven Cy Young awards and two World Series titles . But that December , he was among the players named in an investigative report by former U.S. Sen. George Mitchell on the use of performance-enhancing drugs . The following February , he told the House Oversight and Government Reform Committee that steroid use was `` totally incompatible with who I am and what I stand for . '' `` I can not in good conscience admit to doing something that I did not do , even if it would be easier to do so , '' he told the committee under oath . But in Wednesday 's opening statements , Assistant U.S. Attorney Steven Durham said prosecutors have needles and used cotton swabs that hold the former player 's DNA , as well as residue from anabolic steroids . Those items came from Brian McNamee , a former strength and conditioning coach who claims to have injected Clemens with steroids and human growth hormone . Prosecutors said McNamee held on to the physical evidence for one simple reason : `` He never completely trusted this man , '' Durham said . But Clemens ' lawyer , Rusty Hardin , told jurors McNamee has no credibility . `` Brian McNamee is a liar . He was a liar before this started . He 's still lying to the government , '' Hardin said .
Judge : ` ` I 'd appreciate it if y' all would let me walk home now , '' Clemens tells reporters . References to previous testimony by an ex - client 's attorney had been barred . Music played for the jury included comments about that case . ` ` I do n't see how I can ring the bell , '' judge says .