If this case goes to trial, will the fact that the shooting video has probably been viewed by the jury pool make that much difference in giving Stines a fair trial?
I believe that it doesn't matter much if a juror viewed the video today or at the time of trial. It's clear what the video shows and the evidence that it gives a jury is not debatable.
Sheriff Stines is shown shooting Judge Mullins. The jury will have to decide if Stines is guilty of whatever he is indicted for based on all of the evidence presented to them by both the state and the defense and not just the video. JMO.
I think it makes a big difference. It's not just seeing the video, it's also that the video will get endlessly replayed, talked about and debated over. Everyone in the county will have their opinions set by the time of the trial. Jurors are supposed to go into a trial with an open mind, but it makes it that much more difficult when they have a preconceived notion about what happened. (People who study this sort of thing know that the longer you hold an opinion the harder it is to give it up.)
Additionally, as others have mentioned the video is being shown without any context. And context can be important. How many times have we seen a heavily edited video that causes a huge uproar, and when the full video is shown, it changes how people view the situation? (I don't necessarily think that's what's happening here, but the defense has a right to present its view of what happened immediately following the prosecution's case, and not years later.)