WASHINGTON – Lawyers call them “swearing contests.” Opposing witnesses take the oath–and tell absolutely contradictory stories.

It happens all the time (been in divorce court lately?),  and nobody suggests either witness should face perjury charges.

So the public should take with a grain of salt the claim that New York Yankee pitcher Roger Clemens will precipitate a “possible perjury showdown” (the New York Times’ words, not mine) when he comes to Capitol Hill on Saturday to be questioned by Congressional staff lawyers about allegations by a former trainer that he injected The Rocket with performance-enhancing drugs.

Clemens and the trainer, Brian McNamee, have been issuing contradictory statements for weeks—Clemens saying the injections contained legal substances, McNamee insisting they were illegal steroids and human growth hormones. Now both men have said they will repeat their conflicting stories under oath to Congressional investigators.

On the face of it, this would make a perjury prosecution inevitable—one of them is lying, and should be prosecuted for perjury. Not so (remember all those divorce cases?).

Perjury cases are historically difficult for prosecutors to prove, and here, there seems to be little evidence other than the two men’ claims. Clemens can swear he thought the injections were benign. McNamee can point out that he has no motive to falsely accuse the formidable Clemens, and indeed, under a plea bargain he could go to prison if he is not telling the truth.

So the much-anticipated face-off between the two men under oath on Capitol Hill (currently set for Feb. 13) is not likely to produce a “perjury showdown.” The two men will repeat their now-familiar stories in a “swearing contest” under oath. Then, if reason prevails, the matter will end at that.

– Fred Graham, In Session Senior Editor