In a criminal trial, a jury examines the evidence to decide whether, "beyond a reasonable doubt," the defendant committed the crime in question. A trial is the government's opportunity to argue its case, in the hope of obtaining a "guilty" verdict and a conviction of the defendant. A trial also represents the defense's chance to refute the government's evidence, and to offer its own in some cases. After both sides have presented their arguments, the jury considers as a group whether to find the defendant guilty or not guilty of the crime(s) charged.

(Note: Although a trial is the most high-profile phase of the criminal justice process, the vast majority of criminal cases are resolved well before trial -- through guilty or no contest pleas, plea bargains, or dismissal of charges.)

A complete criminal trial typically consists of six main phases, each of which is described in more detail below:

• Choosing a Jury
• Opening Statements
• Witness Testimony and Cross-Examination
• Closing Arguments
• Jury Instruction
• Jury Deliberation and Verdict

Choosing a Jury

Except for rare cases that are heard only by a judge, one of the first steps in any criminal trial is selection of a jury. During jury selection, the judge (and usually the plaintiff and the defendant through their respective attorneys) will question a pool of potential jurors generally and as to matters pertaining to the particular case -- including personal ideological predispositions or life experiences that may pertain to the case. The judge can excuse potential jurors at this stage, based on their responses to questioning.

Also at this stage, both the defense and the prosecution may exclude a certain number of jurors, through use of "peremptory challenges" and challenges "for cause." A peremptory challenge can be used to exclude a juror for any non-discriminatory reason, and a challenge for cause can be used to exclude a juror who has shown that he or she cannot be truly objective in deciding the case:

• After Juror "A" answers "yes" when asked whether she feels that "street" drugs should be legalized, the prosecution can most likely exclude her for cause from the pool of jurors in a drug possession case, as she has indicated a bias against drug laws.

• The defense can use a peremptory challenge to exclude Juror "B" from the jury pool in a case where a police officer was an assault victim, after it is learned that the juror has two brothers who are police officers. Even if Juror "B" adamantly states that she can remain objective in her assessment of the case, the defense may excuse her without declaring any grounds for doing so.