Washington (CNN) -- Dueling scientists, a former trainer, friends and family are among the witnesses whose testimony a jury will consider as they decide if famed baseball pitcher Roger Clemens lied to Congress during an investigation of steroid use among major league players.
The case against Clemens involves one count of obstruction of Congress, three counts of making false statements and two counts of perjury. He is not charged with illicit use of performance-enhancing drugs, but his denial of such use is part of the case against him.
Federal prosecutor Courtney Saleski, in closing arguments Tuesday, told the jury Clemens "wanted to protect his brand, he wanted to protect his livelihood," in denying the use of steroids during a 2008 investigation by the U.S. House of Representatives into the problem.
"He did that at the expense of our Congress. He threw sand in their eyes. He stole the truth from them," Saleski said.
She said a guilty verdict would give that truth back to lawmakers.
The Clemens defense team disputed whether the government has made its case, telling the jury all the evidence came through a former personal trainer, Brian McNamee, who had incentive to lie.
"You saw Brian McNamee, the only witness in the history of the world who says he gave or saw an injection of that man," said defense attorney Michael Attanasio. "One person in the entire world." During closing arguments, the defense cited the lack of corroborating witnesses, which they said would be a basis for reasonable doubt against any conviction.
"McNamee defines reasonable doubt," Attanasio said, because of perceived inconsistencies, retractions and corrections he made while testifying.
After verbally providing instructions to the jury late Tuesday, U.S. District judge Reggie Walton sent the jury back to begin deliberations, while acknowledging they may only have time to select a foreperson before letting them go for the day.
The trial has run longer than envisioned, and one juror was moved to alternate status Tuesday because of a fellowship in Germany for which he must depart next week. An alternate was then sent back to join the others.
It took about eight weeks for the prosecution and defense to question 46 witnesses, and the most direct conflict came among expert witnesses as to how to interpret a collection of discarded medical items that allegedly link Clemens to steroid use.
Soiled medical wrappings, cotton balls, drug vials and hypodermic needles that McNamee kept were interpreted differently by both sides. Witnesses for the government said genetic material linked with Clemens suggested it was impossible for McNamee to fabricate the evidence.
But defense witnesses on the same topic said storage in a beer can for years allowed commingling and contamination of materials, making reliable conclusions impossible, and the evidence nearly worthless.
"If you have garbage at the start, you'll have garbage at the end," said defense expert witness Dr. Bruce Goldberger, who said his lab would refuse to test such materials without a solid basis for their storage and handling before analysis.
Prosecution witness Dr. Cynthia Morris-Kukoski, an FBI toxicologist, said it is not up to the toxicology lab to make judgments about the materials submitted for testing, with their job only to determine the substances and any genetic identifiers involved.
Former teammate and friend Mike Boddicker testified as to whether Clemens had ever accepted injections, providing an eyewitness account that he had. "I think it was either 1989 or 1990," Boddicker said, referring to their time together with the Boston Red Sox, describing that he "came into the training room, and saw Roger bent over the table with his pants down, getting a shot."
The vial, Boddicker said, was clearly marked "B-12" a substance said to provide a pick-me-up after a game or workout.
This is the second trial for Clemens. A year ago, a mistrial was declared before the case reached the jury. The government's lawyers played video evidence the judge had already banned. Prosecutors said it was an editing mistake, but the Clemens defense team suggested prosecutors were unprepared and had gotten off to a bad start.
"This was a mistake, a regretful mistake," government attorney David Goodhand said in September in arguing for a new trial. But Walton blasted prosecutors for letting inadmissible evidence be shown.
"I would hate to believe they just blatantly disregarded rulings that I made, but it's hard for me to reach any other conclusion," Walton said, before rejecting a defense request that he dismiss the indictment entirely. After consideration, Walton then ordered the new trial.
Several pretrial hearings this time included protests from defense attorneys that the prosecution was trying to take advantage of having heard the initial opening statement last summer by the defense. In the latest trial, defense attorneys expressed concern that prosecutors were trying to "do over" certain efforts the defense may have refuted.
Deliberations Wednesday were set to begin at 1:30 p.m.