The Roger Clemens perjury trial resumes today after a five-day break. Congressional staffer Phil Barnett began testifying last week and will return to the stand as part of the prosecution’s effort to help establish that Congress had authority to investigate drug use in sports, The Associated Press reported. Clemens is accused of lying to Congress by denying he took steroids or human growth hormone. The seven-time Cy Young winner’s first case ended in a mistrial last year because the government introduced inadmissible evidence. Barnett had been on the stand when the mistrial was declared, the AP reported.