Hmmm....well....maybe the DA if exculpatory evidence had been withheld from the defense. But I don't see how the DA could be held personally liable if they acted in good faith.
Juries simply have to sort things out based on the evidence presented by both the defense and the DA and make the best decisions they can with the information they are given and must exclude any and all information they might have heard about the crime or the defendant that came from outside of formal court proceedings. I believe that most juries act in good faith and would not vote for a conviction unless they really thought the defendant guilty. Hard to jail someone for having the courage of their convictions. And think of how hard it would be to convict any criminals if the people on the jury felt that they could be jailed if they got it wrong.
Sure, juries get it wrong sometimes. Occasionally an innocent person is jailed. But more often the guilty party walks - look at the O.J. Simpson murder case.....now there's a jury that ought to have been tossed in the slammer.
