I have just watched the TV series Making a Murderer and have a question regarding the trial with S. Savery and B. Dassey. Whose was the decision that there would be two separate trials. Was it Judge's, Prosecution's or Defence's decision. I would await that given the fact that these two men were according to the prosecution acomplices they would be judged together.
The decision on who to try together is initially made by the prosecutor. A defendant can move to be tried separately.
I can find no record of such a motion but it may have occurred.
I suspect the reason they were tried separately was because Dassey was a minor. State v. Dassey, 2013 WI App 30 (Wis. Ct. App. 2013)