I have, twice. Both times I wound up as foreman.
The criminal case was somewhat interesting, if stupid. It involved possession of a concealed weapon by a parolee. We jurors did a lot of struggling and soul-searching over the confusing testimony of witnesses and finally decided that his girlfriend was just plain lying under oath. Eventually we found the guy guilty, and afterward his attorney as good as admitted it to a couple of us while telling us that a second trial was coming up—in which the defendant was accused of using the weapon that he said he hadn’t had in our trial. “Why didn’t you believe the girlfriend?” he wanted to know, and I said, “Sorry, but I’m not going to help you figure out how to make her testimony more convincing.”
The DUI case was so unnerving that it made me say with considerable feeling: “I hope that neither my fate nor that of anyone close to me winds up in the hands of a jury.” Half of the jurors were of the same ethnicity as the defendant, and they decided on that grounds that he was innocent, because to side against him meant being disloyal to their heritage. That’s as good as saying that no one of their ethnicity is capable of committing an offense; all people of their background are automatically innocent of all crimes. I felt helpless and outraged because the case for the prosecution seemed sound and persuasive to me—and the defense was so idiotic as to be insulting. But nothing would budge those jurors, who had made up their minds that he was being persecuted by racists. The jury ended up hung, and I went out of the courthouse about as disgusted as I have ever been in my life.