Baseball star Rafael Palmeiro will not be prosecuted on perjury charges after lawmakers said Thursday there isn't enough evidence to prove he lied when he told Congress under oath that he had "never used steroids" -- six weeks before failing a steroid test. The investigation did not conclude whether the former Baltimore Orioles slugger had actually ever used performance-enhancing substances prior to his testimony before the House Government Reform Committee. "We couldn't find any evidence of steroid use prior to his testimony," Chairman Tom Davis, R-Va., said in releasing a 44-page report. "That's not a finding of innocence, but it's a finding that we could not substantiate perjury." At issue was Palmeiro's statement at a March 17 hearing: "I have never used steroids. Period." On May 4, he failed a Major League Baseball drug test, coming up positive for an anabolic steroid. In August, shortly after baseball suspended Palmeiro for 10 days, Davis said Congress would look into whether the player committed perjury. "We have a responsibility, an obligation, to investigate it, and that's what we've done," Davis said during a news conference in the same hearing room where Palmeiro had testified.