Trial court judges are responsible for presiding over pre-trial, trial and sentencing hearings, as well 
as probation and parole revocation hearings. They issue search and arrest warrants, set bail or authorize 
release, sentence offenders, engage in pre-sentence conferences with attorneys, work with court clerks, 
bailiffs, jail staff, etc. Trial judges have considerable, but not unlimited, discretion. In addition to the 
ethical and disciplinary rules governing all attorneys in the state, trial judges are subject to judicial codes 
of conduct. Judges are bound by the applicable rules of law when deciding cases and writing their 
legal opinions. Some rules governing judges are flexible guidelines while other rules are very precise 
requirements. 
During the pretrial phase, judges make rulings on the parties’ motions, such as motions to exclude certain 
physical or testimonial evidence, motions to compel discovery, and motions to change venue. Because 
most cases are resolved prior to trial through plea-bargaining, one important judicial function is taking the 
defendant’s guilty plea. 
At trial, if the defendant elects to waive a jury, there is a bench trial, and the judge sits as the “trier 
of fact.” Like jurors in a jury trial, the judge has considerable discretion when deciding what facts were 
proven (or not) by the parties and what witnesses he or she finds credible. When the defendant elects for 
a jury trial, the jury decides what the facts are. In either a bench or jury trial, the trial judge rules: on the 
admissibility of evidence (whether a jury is entitled to hear certain testimony or look at physical evidence), 
whether witnesses are competent, whether privileges exist, whether witnesses qualify as experts, whether 
jurors will be excused from jury service, etc. At the end of the jury trial, the judge gives a set of jury 
instructions to the jurors which informs them on the law that applies to the case they are deciding. 
If the defendant is convicted, then the judge will impose the sentence. Except for death penalty 
cases, jurors are generally not involved with sentencing the defendant.  Judges have perhaps the broadest 
discretion in their role imposing sentences. However, with more states enacting mandatory minimums and 
sentence guidelines, judicial discretion has been severely curtailed. 
“In the eyes of most Americans, the judge is the key player in the courtroom workgroup. The 
symbolism and ceremony of a criminal trial reinforce this view. The judge is seated on a raised bench, 
robed in black, and wields a gavel to maintain order in the courtroom. Moreover, the participants and 
spectators—including the defense attorney and the prosecutor—are commanded to ‘all rise’ when the judge 
enters or leaves the courtroom. It is no wonder, then that the judge is seen as the most influential person in 
court. 
This view of the judge, though accurate to some degree, is misleading for at least two reasons. First, 
although the judge clearly plays an important role—in many cases, the lead role—in state and federal 
criminal courts, other actors play significant supporting roles. This is particularly the case in the majority of 
criminal cases that are settled by plea, not trial. In these cases, the key player may be the prosecutor rather 
than the judge. A second reason why the traditional view of the judge is misleading is that it is based on an 
inaccurate assessment of the role of the judge. Judging involves more than presiding at trials. In fact, most 
Introduction to the American Criminal Justice System
287