A recap of the the hearings so far, from The Associated Press:
WASHINGTON (AP) -- Roger Clemens struggled to find the right words under questioning during a congressional hearing Wednesday and denied new accounts of drug use made against him by former teammate and close friend Andy Pettitte.
Using words like "misremembered" and mispronouncing the last name of his chief accuser, Brian McNamee, Clemens rambled and stumbled during his early remarks on Capitol Hill.
Clemens' reputation and legacy were on the line, and there was the possibility that criminal charges could follow after the seven-time Cy Young winner testified.
"I have never taken steroids or HGH," Clemens said, his voice rising. "No matter what we discuss here today, I am never going to have my name restored."
It seemed clear nearly from the start that the committee would not treat Clemens with kid gloves, despite all the face-to-face sitdowns he did with representatives in recent days -- sometimes posing for photos with or signing autographs for staff members.
Clemens and McNamee were separated by one seat in the same wood-paneled room where Mark McGwire and Rafael Palmeiro once saw their careers tarnished. Clemens briefly stared at McNamee during his accuser's opening statement; for the most part, they did not look at each other.
Members of Congress immediately questioned the credibility of both Clemens and McNamee.
Committee chairman Henry Waxman pointed out inconsistencies in Clemens' comments. Rep. Dan Burton repeatedly read remarks McNamee had made, and each time the former trainer was forced to admit they were untrue.
"This is really disgusting. You're here as a sworn witness. You're here to tell the truth," the Indiana Republican said. "You're here under oath, and yet we have lie after lie after lie after lie, of where you've told this committee and the people of this country that Roger Clemens did things -- I don't know what to believe. I know one thing I don't believe and that's you."
The first congressman to question Clemens, Rep. Elijah Cummings, D-Md., set the tone within minutes, repeatedly reminding Clemens he was under oath and admonishing the pitcher to "keep your voice up." McNamee also was asked to pull his microphone closer.
The hearing started about an hour after several teams opened spring training. This was far from the sunny settings of Florida and Arizona.
Debbie Clemens, the pitcher's wife, sat behind her husband and listened as Waxman implicated her in HGH use, citing statements by Pettitte.
Even one of Clemens' attorneys was given a hard time. At one point, Lanny Breuer stood up from his seat behind Clemens and interrupted a congressman to say he would like to speak in place of his client.
"I'm sorry, the rules don't provide it," Waxman said.
A lawyer who helped prepare former Senate majority leader George Mitchell's report on doping in baseball sat between accuser and accused. It was two hours into the hearing before that lawyer, Charles Scheeler, was addressed by the committee.
IRS Special Agent Jeff Novitzky, a key member of the federal prosecution team against Barry Bonds, also attended the hearing.
Flat-panel televisions on hearing room walls showed evidence, including Pettitte's affidavit.
Pettitte, who was excused from testifying, said in a statement to the committee that Clemens admitted to him as long as 10 years ago that he used HGH. Waxman read from affidavits by Pettitte and Pettitte's wife, Laura, supporting the accusations.
"Andy Pettitte is my friend. He was my friend before this. He will be my friend after this and again. I think Andy has misheard," Clemens said. "I think he misremembers of our conversation."
McNamee told Mitchell that he injected Clemens 16 to 21 times with steroids and human growth hormone from 1998-01. McNamee also said that Pettitte and Chuck Knoblauch used HGH.
"I have helped taint our national pastime," McNamee said. "Make no mistake: When I told Sen. Mitchell that I injected Roger Clemens with performance-enhancing drugs, I told the truth. I told the truth about steroids and human growth hormone. I injected those drugs into the body of Roger Clemens at his direction. Unfortunately Roger has denied this and led a full-court attack on my credibility. And let me be clear, despite Roger Clemens' statements to the contrary, I never injected Roger Clemens -- or anyone else -- with lidocaine or B-12."
Waxman said McNamee, a former New York City police officer, lied to police seven years ago during an investigation of a possible rape. He also was tough on Clemens.
"We have found conflicts and inconsistencies in Mr. Clemens' account. During his deposition, he made statements that we know are untrue," Waxman said, adding that some of Clemens' statements "are simply implausible."
In his statement, McNamee made new accusations.
"I have had that opportunity to think about these events and consider the specific drug regimens we used," McNamee said. "As a result, I now believe that the number of times I injected Roger Clemens and Chuck Knoblauch was greater than I initially stated."
McNamee worked with Clemens for several years. Still, he added: "While I liked and admired Roger Clemens, I don't think that I ever really trusted him."
Bonds, baseball's home run king, was indicted in November on charges of perjury and obstruction of justice stemming his 2003 testimony to a grand jury in which he denied knowingly using performance-enhancing drugs. Because of his denials under oath, Clemens could be subjected to a similar criminal probe.
"Coming into today's hearing, we have before us some very different stories. They're in many ways incompatible," said ranking Republican Tom Davis of Virginia, who presided over the committee's 2005 session with McGwire, Palmeiro, Sammy Sosa and other stars. "Someone is lying in spectacular fashion about the ultimate question."
It was at that hearing where McGwire was vague while answering many questions. Cummings demanded to know if the slugger was "taking the fifth", referring to the fifth amendment.
McGwire responded by timidly saying "I am here to talk about the future not about the past". The exchange came to epitomize the entire inquiry.
In a reference to that day, Rep. Mark Souder, R-Ind., admonished Wednesday's witnesses by saying: "It's better not to talk about the past than to lie about the past."
Pettitte issued a statement shortly before the hearing started and acknowledged using HGH in 2004. In December, he admitted taking HGH for two days in 2002.
Last week, Pettitte was asked to discuss drug use in a deposition and affidavit before a congressional committee.
"In that affidavit, Andy informed the committee that in addition to the two shots a day of HGH he took for two days in 2002, he also took HGH for a one-day period in 2004, shortly preceding season-ending elbow surgery," his lawyer, Jay Reisinger, said in a statement released to The Associated Press.
"Andy had not previously mentioned this usage because he acquired the substance from his father, who had obtained it without Andy's knowledge in an effort to overcome his very serious health problems, which have included serious cardiac conditions."
In the affidavit, Pettitte said that Clemens told him nearly 10 years ago that he used HGH. Pettitte also said Clemens backtracked when the subject of HGH came up again in conversation in 2005, before the same House committee held the first hearing on steroids in baseball.
Pettitte said in the affidavit that he asked Clemens in 2005 what he would do if asked about performance-enhancing substances, given his admission years earlier.
Pettitte said Clemens responded by saying Pettitte misunderstood the previous exchange in 1999 or 2000 and that, in fact, Clemens had been talking about HGH use by his wife in the original conversation.