Who picks the jury for a federal trial?

You haven't learned much in your classes yet have you. You don't accuse someone of a Federal Crime, you take your suspicions/evidence to the Federal Prosecutors office in your district and they follow up with a formal investigation. Federal jury pools are selected from a district wide list and most often from residents of the city in which the court is located. Since those are usually large cities the pool being local prevents the possibility of having to commute long distances to serve.