What to know about Clemens' trial

Jury selection will begin on Wednesday in U.S. v. Roger Clemens, a trial that could close the door on the steroid era in baseball and lead to arguably the best pitcher in the last 30 years being sentenced to prison. Michael McCann breaks down what to expect.

1) What is this case fundamentally about?

The case centers on whether Clemens knowingly lied before Congress in February 2008 when he stated, without equivocation, that he never used steroids, Human Growth Hormone (HGH) or any other illegal performance-enhancing drugs (PEDs).

Led by Assistant U.S. Attorneys Daniel Butler and Steven Durham (who prosecuted Miguel Tejada for lying to Congress regarding PEDs and obtained a misdemeanor guilty plea), prosecutors will maintain that Clemens repeatedly lied. They intend to prove that through a mix of witnesses, including Clemens' former trainer, Brian McNamee, and former teammate, Andy Pettitte, and physical evidence, including syringes and other drug paraphernalia that allegedly connect Clemens' DNA to substances he denies using.

Clemens' defense will focus on credibility and recollection issues of the witnesses, such as whether McNamee's checkered past should lead jurors to question his truthfulness or whether Pettitte may have simply misheard Clemens. The defense will also portray the physical evidence -- much of which was provided by McNamee -- as unreliable and possibly tampered.

• Roger Clemens' perjury trial set to begin Wednesday

Prosecutors will need to convince a jury of 12, beyond any reasonable doubt, that Clemens is guilty. While their burden is high, federal prosecutors win about 90 percent of their trials. On the other hand, Clemens has financial resources to wage an expensive and thorough defense that defendants typically do not enjoy.

The trial is expected to last four to six weeks and will be heard before U.S. District Judge Reggie Walton, who in 2007 presided over the trial of Vice President Dick Cheney's former chief of staff, Scooter Libby. After opening statements from each side, the prosecution will present its case first, and then Clemens' attorneys, most notably Rusty Hardin and Michael Attanasio, will present his case. If, after the prosecution presents, Clemens and his attorneys feel confident that they will obtain a not guilty verdict, they may condense their defense, which would result in a shorter trial.

2) What charges does Clemens face?

Clemens faces six charges. The first charge is for obstructing Congress in its investigation into the accuracy of the Mitchell Report as it related to Clemens' purported use of PEDs. According to prosecutors, Clemens knowingly made 15 false statements while under oath. Most of the statements relate to Clemens' denials that he used HGH and PEDs, while other statements concern recollections of fact, such as his insistence that, contrary to McNamee's contention, he was not at Jose Canseco's house on or about June 9, 1998.

Charges 2, 3 and 4 concern Clemens' purportedly false statements to Congressional staff about his alleged use of HGH, steroids and Vitamin B12. As with Barry Bonds, who faced a perjury charge for knowingly lying about whether he was injected by someone other than his doctor, prosecutors have incorporated a charge that does not technically require them to prove that Clemens used illegal substances. Count 4 simply states that Clemens knowingly lied when asserting that McNamee injected him with Vitamin B12, a legal substance.

Counts 5 and 6 concern similar facts. They charge that Clemens committed perjury while testifying before the House Oversight Committee on February 13, 2008.

3) If Clemens is convicted, will he be sentenced to prison and if so, for how long?

If Clemens is convicted on all six charges, he would face a recommended sentence of 15 to 21 months, though Judge Walton is not bound by sentencing guidelines and could assign a stiffer or lighter sentence. It would be a near certainty, however, that Clemens is sentenced to prison.

If Clemens is only convicted on one or two charges, he would likely receive a shorter sentence, such as six months, or possibly home confinement; Judge Walton would enjoy substantial discretion.

If there is a hung jury, meaning the 12 jurors cannot unanimously agree on a charge, then prosecutors would preserve the right to retry him at a later date. A hung jury would not be a fluke outcome. Consider Bonds, who was convicted on one count of obstruction of justice in April but received a hung jury on three counts of perjury. He will find out in the next few months whether he faces retrial.

4) Will Clemens testify?

Although Clemens would probably like to testify, he probably won't. The Fifth Amendment commands that defendants in criminal trials only testify if they so choose. Juries, moreover, are instructed by the judge to not draw any adverse inferences from a defendant's decision to refrain from testifying.

Clemens' attorneys will likely assure him that they will be able to effectively attack the prosecution's case and that his testifying would be too risky, even if Clemens is in fact telling the truth. The goal of a criminal defense attorney is not prove a defendant's innocence per se; rather, it is to prove that there is reasonable doubt in the prosecution's case, and thus the jury must find the defendant not guilty.

If McNamee turns out to be a less-than-credible witness, then much of the government's case against Clemens would be compromised and the defense would be poised to secure a not guilty verdict. In that scenario, having Clemens testify would be a dubious strategy for at least two reasons. First, Clemens would have to face difficult cross-examination questions from seasoned and talented prosecutors who win about 90 percent of their trials; if he struggled with questions from members of Congress, how would he do with questions from prosecutors? Second, the jury's focus would turn from the believability of McNamee to that of Clemens, who would likely labor to explain certain aspects of his defense.

But if McNamee holds up well against cross examination -- and he spoke well before Congress in 2008 -- and if the government's other witnesses and physical evidence seem persuasive, Clemens may need to testify in order to avoid conviction. Whether he does well or poorly, Clemens on the stand would undoubtedly offer some of the trial's most dramatic moments.

5) If Clemens doesn't testify, who will be the most important witness?

While unheralded witnesses can occasionally stun the courtroom, there are two well-known witnesses who are poised to make a big impact: Brian McNamee and Andy Pettitte.

The government's case is built largely on McNamee's sworn testimony that he injected Clemens with steroids and HGH and the physical evidence McNamee has shared to prove it. McNamee is the only witness who will say that he saw Clemens receive illegal PEDs.

If McNamee proves unbelievable, the jury may be unwilling to convict Clemens. For that reason, Clemens' attorneys will wage a full-scale attack on McNamee's credibility. They will portray him as a drug dealer, with shady connections and disreputable business dealings. They will openly wonder why for years McNamee would insist that Clemens never took steroids, but then, seemingly to avoid prosecution, he turned his story around 180 degrees to implicate Clemens. They will also attempt to ask McNamee about accusations that he drugged and raped a woman in Florida in 2001, and doubts police had about McNamee's statements. Prosecutors will object to the inclusion of those accusations as irrelevant to Clemens' case and as overly prejudicial to McNamee, who was not charged with a crime. Judge Walton's ruling on those accusations' admissibility could prove crucial, because if the jury believes McNamee sexually assaults women, they may have a hard time overlooking their dislike of him in what he has to say about Clemens.

To support McNamee's claims against Clemens, the prosecution will call several former big league players to the stand. David Segui and C.J. Nitkowski are expected to say that before McNamee worked out a deal with prosecutors to avoid prosecution, he confided in them that he had injected Clemens with illegal PEDs. Their testimony would imply that McNamee did not entirely change his story to law enforcement officials to avoid prosecution.

The testimony of two of Clemens' former teammates, Chuck Knoblauch and Mike Stanton, may also aid McNamee. They are expected to detail how they knowingly obtained illegal PEDs from McNamee, who "worked" with a number of MLB players on using illegal substances. The strategy of guilt-by-association may not work, however. Bonds avoided conviction on perjury charges despite other players saying they knowingly received steroids from his trainer, Greg Anderson.

Prosecutors are also planning to call Jose Canseco to the stand. He is expected to say that, as McNamee claims, he and Clemens discussed steroids at Canseco's house in 1998. Clemens insists he was golfing that day. If the jury believes that Clemens was indeed golfing, then it would undercut McNamee's credibility. If the jury believes Canseco and McNamee, Clemens' defense would take a hit.

There are still other witnesses who will corroborate McNamee, including former New York Mets clubhouse employee Kirk Radomski, who worked out a plea deal with the government in exchange for speaking with the Mitchell Commission. Radomski, whose credibility will draw rebuke from Clemens' attorneys, is expected to testify that he worked with McNamee on obtaining PEDs for Clemens.

If McNamee's credibility comes under heavy fire, prosecutors can still rely on Clemens' former teammate and close friend, Andy Pettitte, to present a believable account as to Clemens knowingly lying under oath. Pettitte, who lacks the controversies and character issues that could doom McNamee's testimony, is expected to testify that Clemens confided in him in 1999 or 2000 that he used illegal performance enhancers.

Instead of attacking Pettitte's credibility, defense counsel will go at his memory of a lone conversation from long ago. They will ask Pettitte to provide details of the conversation in which Clemens allegedly confided. They will dwell on any possible inconsistencies in Pettitte's statements about the conversation, especially if Pettitte adds or omits detail while on the stand. Pettitte has no reason to lie and the jury will be inclined to believe him, but if his memory seems hazy, his testimony will lose most of it impact.

6) How important is scientific evidence in this trial?

Scientific evidence should prove very important. Although Clemens' attorneys will object (probably without success), the government will try to introduce an assortment of incriminating items, including syringes, cotton swabs, fingerprints and DNA samples, that they will say prove a link between Clemens and substances he denies using. Several days will likely be devoted to the introduction of these items and testimony by those who handled and studied them.

McNamee will return as a central figure when these items are discussed. He stored them in his basement for several years before turning them over to prosecutors. Clemens' attorneys will characterize the items as improperly -- and unscientifically -- stored and as susceptible to tampering.

7) Is Clemens making a mistake by entrusting Rusty Hardin to keep him out of prison?

To date, Hardin has received much criticism for his representation. While it is possible that Clemens, clearly confident in his innocence, has simply ignored Hardin's good advice, Hardin probably would not have continued to serve as Clemens' lawyer if he and Clemens disagreed about strategy. And the strategy has not worked, especially in regards to four big decisions: that Clemens go on 60 Minutes; that Clemens encourage Congress to invite him to testify; that Clemens try to charm his way through Congress before his testimony; and that Clemens file a defamation lawsuit against McNamee. The 60 Minutes interview was poorly received and is now evidence in the government's case, most members of the House Oversight Committee did not believe or seemingly like Clemens and later asked the Justice Department to look into perjury charges and the defamation lawsuit is not only unlikely to succeed, but it contributed to the New York Daily News reporting on an alleged affair between Clemens and singer Mindy McCready.

Hardin, however, could redeem himself in the forum in which he has enjoyed the most professional success: the courtroom. Hardin has successfully defended other high-profile clients against criminal charges, including NBA Hall of Famer Calvin Murphy, who in 2004 faced charges for sexual assault and indecency with a child. In other words, Hardin may have been ill-suited for representing Clemens in the past, but now could be the right person.

Hardin will also have help, namely attorney Michael Attanasio, a former federal prosecutor who joined the Clemens legal team in August 2010. Attanasio is very familiar with the Mitchell investigation, as he provided legal advice to the San Diego Padres during it. While Hardin may attract the most headlines, expect Attanasio to play a crucial role in the trial. He will deliver the cross-examination of Pettitte, who Attanasio represented for less than a week in 2007.

8) Regardless of what happens, does the Clemens trial end the steroid era in baseball?

There may never be an "end" to the use of steroids and illegal PEDs in baseball, since there will always be financial incentives for some trainers, scientists and doctors to develop substances, or even medical procedures, that enhance performance and evade detection under existing testing policies. Similarly, players are always looking for an edge that might prove the difference between mediocrity or stardom, or playing in Triple-A or the big leagues.

That said, and depending on whether Bonds is retried, the juice-aided home run era of the mid 90s to the mid 2000s will receive closure at the conclusion of the Clemens trial. Along those lines, do not expect any additional prosecutions on perjury, especially since the statute of limitations on federal perjury charges is five years. So the most recent steroid era will indeed be ending.

Michael McCann is a sports law professor and Sports Law Institute director at Vermont Law School and the distinguished visiting Hall of Fame Professor of Law at Mississippi College School of Law. He also teaches a sports law and analytics reading group at Yale Law School. Follow him on Twitter.