The New York Times’ Michael B. Schmidt reports this evening that federal authorities prepping a perjury case against Roger Clemens have found performance-enchancing substances on the needles Brian McNamee claims were used to inject the Rocket.

In February, it was disclosed that federal prosecutors had linked Clemens™s DNA to blood residue in at least one of the syringes that McNamee handed over to authorities. Clemens has not denied that McNamee injected him, but he has maintained that the substances McNamee used were Vitamin B12 and the painkiller lidocaine.

The United States Attorney™s Office for the District of Columbia convened a grand jury as part of its investigation into whether Clemens committed perjury when he told Congress last year that he had never used performance-enhancing substances. Those assertions directly contradicted statements that McNamee also made under oath.

If the federal prosecutors move to indict Clemens and seek to use the substances found on the drug paraphernalia as evidence, Clemens™s lawyers are expected to question their authenticity and the chain of custody. Clemens™s lead lawyer, Rusty Hardin, said Monday night that he was not surprised to learn that performance-enhancing substances had been found.

œDuh, he said with exaggeration. œDo you really think McNamee was going to fabricate this stuff and not make sure there were substances on there? The fact is Roger never used steroids or H.G.H.

Jennifer L. Mnookin, a professor of law at U.C.L.A., said that a judge would most likely deem the drug paraphernalia admissible and allow a jury to assess its credibility.

œThe presence of Clemens™s DNA alone makes these materials an important part of the case and makes it likely that the judge would let them in and let the jury weigh whether to believe that they are authentic, she said.

Clemens lawyers, she added, would most likely argue that the materials were fabricated or contaminated.

œAnd at that point, Mnookin said, œa jury will be back at square one, trying to decide whether they believe McNamee or Clemens.