Emerod

Hi This is my first topic, ive looked but cant find a clear answer. My question is who would be he actual jusge in a criminal trial in Rome? specifically the late republican era? Would it be the Prateor or one of the minor magistrates (Vigintiviri) or someone else? I keep reading conflicting thigns, some saying the praetor appointed a judge if so from where? who was this judge? a senator? some other kind of offccial? also how large was a jury? Im talking in terms of both small petty crimes and large violent creims. I kknow most people hear watch HBO's Rome so lets use that as an example. In the episode where Pullo killed that guy and was put on trial who would the judge and jury have been? Prateor, minor magistrate, or someone else?