Boston city councilor Chuck Turner was recently convicted of taking a bribe from a man who sought a liquor license. The man was an FBI informant and the transaction was secretly videotaped. At his trial, Turner testified in his own defense. As reported in the Globe, it didn’t go well.

I don’t know much about Turner and I didn’t follow this case very closely, but it seems to illustrate a lesson I learned years ago while working as a criminal defense attorney: Your chances of obtaining a Not Guilty verdict are higher if the defendant does not testify. That statement seems contrary to common sense. You would assume that in deliberations, individual jurors, if not the jury collectively, couldn’t help but speculate “if he has nothing to hide, why doesn’t he tell his side of the story?” While that is certainly true, the harm that typically results from the defendant testifying greatly outweighs any benefits. Even if the defendant truly is not guilty, there has to be some evidence that points towards him or at least something shady in this background. Add to that the normal nervousness anyone experiences when on the witness stand and a seasoned prosecutor can do a devastating cross-examination. When the jury adjourns to its deliberations, their focus is entirely on the defendant and his testimony. With the jury’s decision largely influenced by its feelings regarding the veracity of the defendant’s testimony, the chances of a conviction increase.

Compare that scenario to one where the defendant did not testify. While the jury might have some questions about that decision, the judge specifically instructs them not to consider that, to not even mention it. Without any testimony from the defendant to discuss, the scrutiny of the jury shifts to the prosecution’s evidence and the possible holes in it, holes that have been highlighted by the defense lawyer throughout the trial. Jurors take to heart the instruction that they may only convict a defendant after finding proof “beyond a reasonable doubt.” That’s a tough term to define, but the jury instruction in Massachusetts says it’s more than possibly and it’s more than even probably – you must be convinced “to a moral certainty.” That’s a pretty high standard. And as I used to say in my closing arguments, “the law says that if you have a reasonable doubt, the defendant is entitled to the benefit of that doubt and you must find him not guilty.”

The outcome of any jury trial is impossible to predict. There are far too many variables that go into the outcome of any trial. Still, I found that jurors in criminal cases were very diligent about scrutinizing the prosecution’s evidence and, when it was lacking, saying Not Guilty. When the defendant testifies, less scrutiny is given to the prosecution’s case and the chances of conviction increase substantially.