That is the wrong question -- if a juror is that certain, pre-trial, that a defendant is guilty, there is no way that the defendant can get a fair trial.
> if a juror is that certain, pre-trial, that a defendant is guilty, there is no way that the defendant can get a fair trial
Sure they can, one nutjob juror cannot convict.
I've also been seated on juries where some of my fellow jurors were quite obviously biased against the defendant, and this really hurt their credibility with me. I wasn't the only one either, other jurors challenged some of the statements they made and it was clear to me that they also picked up on the bias and rejected it.
My first time on a jury a pleasant looking retired white man said he wanted to be foreman, for a trial of a Hispanic youth, and the guy started with "well he's obviously guilty right?" and he was serious. This was met with total outrage from several others on the jury and the foreman sat there meekly for the rest of the deliberations. The rest of us carefully reviewed the evidence and the defendant absolutely received a fair trial.
One nutjob juror cannot convict, but one person can prevent a unanimous verdict by refusing to cooperate or objectively evaluate testimony and follow the rules. The result of that in many cases is a hung jury and then a mistrial.
Combine this with the concept of jury nullification (something law enforcement DESPISES) and there are lots of situations where it would make sense for a juror to refuse to align with the rest of the jury.
Fuck ... I hated that so much. I loved the actual courtroom experience, I learned so much about how our legal system worked and both sides’ lawyers did an excellent job in explaining the case from their view points. By the end, it was pretty clear to the majority of us which party had the better case .... except for one old lady who wanted to “stick it to the man” and hated both parties. 4 ish days of deliberation trying to get her to put aside her biases. Eventually we were able to explain it to her and she stepped down (after we pointed out it’d be a waste of everyone’s time, including hers, if we didn’t come to a decision), but man it sucked until then. It was a complex business case, and it required a unanimous jury vote.