There are risks in calling a defendant to the stand, particularly when the jury might perceive the defendant as arrogant or unlikeable, or when cross-examination is likely to poke holes in the defendant's testimony. But this is an overstatement:

"Any good defense attorney will do his best to have his client not testify," said Jason Brown, a former federal prosecutor who is now a securities lawyer in the New York office of Holland & Knight. "The defense would rather concentrate on weaknesses in the government's case."

In fact, any good defense lawyer will prepare the defendant to testify, will continue to assess the case throughout the trial, and will make a final decision when the time comes. If an acquittal seems likely without the defendant's testimony, there's no need to risk a poor performance on the witness stand. But if the jury's view of the evidence is unclear to the defense (as it often is), the defense may decide to give the jury what it wants: a chance to hear the defendant speak for himself.