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: Though a trial is the most high profile phase of the criminal justice process, most criminal cases are resolved well before trial -- through "guilty" or "no contest" pleas, plea bargains, or dismissal of charges. In particular, most DUI cases do not reach the trial stage. In the majority of these cases, the arraignment usually represents the first and last time the defendant will be in court, as most DUI offenders choose to plead guilty or enter into a plea bargain in order to avoid a trial, especially if the government's evidence is strong.)
A complete criminal trial typically consists of six 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
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.
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.
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.
After the government concludes its case-in-chief, the defense can present its own evidence in the same proactive manner. However, in some cases the defense may choose not to present a "case-in-chief," instead deciding to make its key points through cross-examination of the government's witnesses, and challenges to its evidence.
Once the prosecution and defense each have had an opportunity to present their case and to challenge the evidence presented by the other, both sides "rest," meaning that no more evidence will be presented to the jury before closing arguments are made.
Similar to the opening statement, the closing argument offers the government and defense a chance to "sum up" the case, recapping the evidence in a light favorable to their respective positions. This is the final chance for the parties to address the jury prior to deliberations, so in closing arguments the government seeks to show why the evidence requires the jury to find the defendant guilty. In turn, the defense tries to establish that the government has fallen short of its "burden of proof," so that the jury must find the defendant "not guilty."
After both sides of the case have had a chance to present their evidence and make a closing argument, the next step toward a verdict is jury instruction -- a process in which the judge gives the jury the set of legal standards it will need to decide whether the defendant is guilty or not guilty.
The judge decides what legal standards should apply to the defendant's case, based on the criminal charges and the evidence presented during the trial. Often, this process takes place with input and argument from the prosecution and defense. The judge then instructs the jury on those relevant legal principles decided upon, including findings the jury will need to make in order to arrive at certain conclusions. The judge also describes key concepts, such as "guilt beyond a reasonable doubt," and defines any crimes the jury may consider, based on the evidence presented at trial.
For example, if the defendant has been charged with voluntary manslaughter, the judge may:
- Define the elements of voluntary manslaughter, the charged crime;
- Define the elements of related crimes such as involuntary manslaughter and second-degree murder; and
- Set out the findings the jury would need to make in order to convict the defendant of each of those crimes.
The case then goes "to the jury."
After receiving instruction from the judge, the jurors as a group consider the case through a process called "deliberation," attempting to agree on whether the defendant is guilty or not guilty of the crime(s) charged. Deliberation is the first opportunity for the jury to discuss the case, a methodical process that can last from a few hours to several weeks. Once the jury reaches a verdict, the jury foreperson informs the judge, and the judge usually announces the verdict in open court.
Most states require that a jury in a criminal case be unanimous in finding a defendant "guilty" or "not guilty." In such states, if the jury fails to reach a unanimous verdict and finds itself at a standstill (a "hung" jury), the judge may declare a "mistrial," after which the case may be dismissed or the trial may start over again from the jury selection stage.
See also: What happens at trial?