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.

Opening Statements

Once a jury is selected, the first "dialogue" at trial comes in the form of two opening statements -- one from the prosecutor on behalf of the government, and the other from the defense. No witnesses testify at this stage, and no physical evidence is ordinarily utilized.

Because the government has the "burden of proof" as to the defendant's guilt, the prosecutor's opening statement is given first and is often more detailed than that of the defense. In some cases, the defense may wait until the conclusion of the government's main case before making its opening statement. Regardless of when opening statements are made, during those statements:

• The prosecutor presents the facts of the case, from the government's perspective, and walks the jury through what the government will try to prove -- what the defendant did, how, and why.
• The defense gives the jury its own interpretation of the facts, and sets the stage for rebutting key government evidence and presenting any legal defenses to the crime(s) charged.

Witness Testimony and Cross-Examination

At the heart of any criminal trial is what is often called the "case-in-chief," the stage at which each side presents its key evidence to the jury.

In its case-in-chief, the government methodically sets forth evidence in an attempt to convince the jury beyond a reasonable doubt that the defendant committed the crime. It is at this point that the prosecutor calls eyewitnesses and experts to testify. The prosecutor may also introduce physical evidence, such as photographs, documents, and medical reports.

Whether a witness is called by the government or the defense, the witness testimony process usually adheres to the following timeline:

• The witness is called to the stand and is "sworn in," taking an oath to tell the truth.
• The party who called the witness to the stand questions the witness through "direct" examination, eliciting information from the witness through question-and-answer, to strengthen the party's position in the case.
• After direct examination, the opposing party has an opportunity to question the witness through "cross-examination" -- attempting to poke holes in the witness's story, attack their credibility, or otherwise discredit the witness and his or her testimony.
• After cross-examination, the side that originally called the witness has a second opportunity to question him or her, through "re-direct examination," and attempt to remedy any damaging effects of cross-examination.