WASHINGTON -- Former Major Leaguer David Segui testified at the federal perjury trial of Roger Clemens on Thursday, backing up Brian McNamee's claim that the strength and conditioning trainer saved evidence he used to inject players with performance-enhancing drugs in order to placate his wife."He mentioned he had kept darts to get his wife off his back," Segui said of a 2001 phone conversation with McNamee during an appearance of about an hour on the witness stand, using "darts" as slang for needles. Segui's testimony might give jurors a little more reason to believe McNamee's account of when and why he kept items he says implicate Clemens. Meanwhile, the prosecution's case is about to enter a new and crucial final phase with testimony about DNA analysis of the evidence. The government called several scientists as witnesses Thursday, and by the end of the day had called an expert witness who figures to introduce DNA evidence relating to the items saved by McNamee that the former strength and conditioning trainer says he used to inject Clemens. The testimony of Alan Keel, a DNA expert for Forensic Science Associates, could wind up being among the most critical in the trial for the government, because it is expected to at least begin to link Clemens' DNA, which he voluntarily provided, to items McNamee said he used on Clemens, then kept for several years. Keel, an experienced DNA expert based in Hayward, Calif., testified in general terms what DNA is and how it is sampled from items as part of investigations, but other than saying he'd been asked to analyze items relating to the Clemens trial had not yet specifically addressed any analysis for this case. Keel will return to the stand when the court reconvenes Friday morning at the U.S. District Court for the District of Columbia. Earlier, Federal Bureau of Investigation Laboratory Chemical Unit forensic examiner Pamela Reynolds and former Anti-Doping Research scientist Jeremy Price testified that steroids were found on some of the items McNamee kept. Their testimony was met with cross-examination from defense attorney Michael Attanasio that pointed out their findings could not be linked to Clemens and, especially in the questioning of Price, intimated to the jury that the items could have been manipulated by McNamee, as the defense suggested in its opening statement. Clemens is charged with three counts of making false statements, two counts of perjury and one count of obstruction of Congress based on his testimony during a Feb. 13, 2008, hearing before the House Committee on Oversight and Government Reform and a Feb. 5, 2008, deposition conducted by committee staff members. Clemens said at the hearing, "Let me be clear: I have never used steroids or HGH." Clemens testified that McNamee only ever injected him with vitamin B12 and lidocaine. McNamee, who served as a strength and conditioning trainer to Clemens in one capacity or another for nearly a decade, said in his own deposition and at that same hearing that he had injected Clemens with performance-enhancing drugs on numerous occasions, keeping items he says proves it for several years in a beer can and a mailing box. In the midst of the sometimes complicated and multisyllabic testimony from scientists, Segui became the second Major League player to take the stand in the trial, following Andy Pettitte's appearance three weeks earlier. Segui's appearance on the stand was confirmed earlier Thursday when Judge Reggie Walton granted a government motion to have Segui and investment manager Anthony Corso testify about things McNamee told them in order to rebut defense claims of bias and self-interest raised in its cross-examination of McNamee. Segui, who played 15 Major League seasons for seven different teams, was under subpoena in the case and was required to testify about McNamee's prior consistent statements in the trial once Walton granted the government's motion. After establishing that Segui, now 45, had met McNamee when he was traded to Toronto in 1999 -- one year after Clemens went to the Yankees and one year before McNamee reunited with Clemens there -- and the two developed a friendly working relationship, Assistant U.S. Attorney Gilberto Guerrero asked Segui about a conversation he had with McNamee sometime in 2001. "He made a phone call to me and I could tell he was frustrated, stressed out," Segui said. "He was having problems with his wife. ... He mentioned that the relationship between Brian and Roger had put stress on his married life." Segui later added that McNamee said it was the "being gone, leaving at the drop of a hat to go train" Clemens that stoked the marital problems. Segui's testimony was meant to corroborate McNamee's story that he took items home after injecting Clemens with steroids in August 2001 in order to show his wife, and that she convinced him to keep them. But a second conversation Guerrero tried to enter was disallowed by Walton because Segui couldn't pinpoint the time frame of the conversation, or even venture a guess when it was. "You're asking the wrong guy about dates. I don't keep a log of my life," Segui said at one point. During cross examination, Attanasio made it clear that the conversation did not mention any use of PEDs by Clemens, and that Segui had no firsthand knowledge of Clemens ever using the substances. "All I know is what I was told," Segui said. "I never saw it, I never asked to see it." Unlike Pettitte, Segui was not accompanied by an attorney, and he left the courthouse moments after his testimony and looked for a taxi. Asked outside the courthouse for a comment about his appearance, he politely declined, saying, "I don't want to get into it." The government also will introduce testimony that sometime in 2002 to 2004 McNamee told Corso, one of his Wall Street training clients, that Clemens used HGH to help with recovery and in 2005 told Corso about keeping the evidence. Many of the items McNamee kept were once again on display Thursday as the first two scientists testified about what steroids were found on needles, in vials and small glass containers called ampules and other materials McNamee turned over to the government in January 2008. Reynolds, the FBI chemist, testified that a syringe, vials and ampules from the evidence McNamee saved tested positive for having residue of steroids. But Attanasio, who raised the issue of cross-contamination because of the way McNamee stored the items, was quick to point out there was no way to say how the steroids got there, who used them or if anybody at all used them. "I can only tell you the chemicals that are in this evidence," Reynolds said. The testimony of Price included the detection of several different testosterone esters, or chemical compounds, and steroids found on two needles and cotton balls among the McNamee evidence. Price also testified on direct examination by Assistant U.S. Attorney Daniel Butler that none of the items tested positive for a specific type of vitamin B12 or lidocaine, but Attanasio on cross pointed out there are other types of B12 and other types of lidocaine for which the lab did not test. Attanasio also worked hard to suggest that McNamee might have used items to inject Clemens with B12 and lidocaine and then washed out and tainted the items with steroids. At the end of the day, government lawyers said they only had two or three more witnesses to present, so it's quite possible the prosecution may rest its case Friday and the defense may begin its presentation sometime during the day, beginning with FBI agent John Longmire -- who testified at length for the prosecution and has been at the government's table in the courtroom for the duration of the trial.
John Schlegel is a national reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.