Does the GJ decide what can or cannot be presented as evidence, or only if there is enough evidence to bring charges? Or both?
They decide whether or not somebody will be charged for a crime and if so, what the charge will be.
The charge is called "returning a bill" or "giving a true bill" as it varies a bit from state to state. I've heard it called an "information" also. It's all the same stuff.
The mechanics stay the same. Once the Grand Jury returns this "bill", that is formalized into an "indictment" which is really no different than getting a criminal complaint.
The Grand Jury is a charging mechanism to get the ball rolling.
They do not have the power or authority to decide on evidence or how a case will be presented in the regular courtroom at the trial.
That job is left to the dueling lawyers, both at trial and via pre-trial motions
(you can do motions ahead of time, before the actual trial, to try to keep evidence out of the hearing of a jury). Later on in this case, you'll probably hear the term: "motions in limine." It is just a fancy term for trying ahead of time to keep stuff out of the hearing of the jury---for example, a mere objection wouldn't suffice as the question itself is so prejudicial it can affect the trial outcome. So when you hear that term in a few, that's all that is.
But even then, the dueling lawyers present arguments , objections, about evidence...it is the Judge who decides to let it in or exclude it from the proceedings and he /she is attempting to follow strict rules of evidence.:gavel:.
Hope that helps :wink: