From the commission of a crime to the arrest, prosecution and conviction of an offender, the criminal justice process can be lengthy and complicated. Each state has its own regulations and procedures that govern proceedings. The federal system plays by its own rules, too. Despite substantial differences, the criminal justice process usually takes a fairly standard course.

Investigation: Gathering Evidence & Following Leads

After a crime has been committed, the criminal justice process begins with investigation. Law enforcement officers can be tipped off to a potential crime through a number of avenues, including 911 calls and reports from crime victims. Even easier, and certainly more immediate, the police can notice signs of potentially-criminal behavior and investigate the situation of their own volition. Highway patrol officers pull over millions of drivers every year after observing traffic violations, from speeding to driving while intoxicated.

Next, law enforcement officials begin to gather evidence, hoping to discover whether or not a crime was committed and, if so, who committed it. Police officers secure the crime scene, while specialized crime scene investigators search for physical evidence and, after careful preservation, send it to a crime lab. Here, forensic scientists analyze the evidence in a laboratory and ultimately forward their results to a detective assigned to the case. Meanwhile, detectives interview witnesses (including victims) who saw or experienced what happened.

Law enforcement officials may have to go further afield for some details, collecting circumstantial evidence from people who, while not present to see the crime take place, may have relevant information. Detectives usually follow these “leads,” hoping to determine who committed the crime and how to find them.

Lawful Search & Seizure

When access to a private structure is necessary, officers need to secure a warrant, a document, issued by a judge, giving them the right to search the property. Judges review the information submitted by police to decide whether or not the officers have “probable cause” – sufficient evidence to buttress a reasonable belief that crime occurred at the location. Officers must swear (or give their “oath”) that the information is true to the best of their knowledge – with penalties for intentional lies.

Under the Fourth Amendment of the Constitution, citizens of the United States have “the right […] to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures.” Search warrants are written into the Constitution; the government only has a right to enter or seize private property after “probable cause” has been demonstrated and a warrant has been issued. To remain constitutional, warrants must specify the location to be searched, along with the suspects or items that the officers believe will be found there.

In some cases, “exigent circumstances” can remove the need to acquire a search warrant. When police or other law enforcement officials believe that an active crime is underway, or that waiting for a warrant would allow time for crucial evidence to be destroyed, a valid warrant may not be required. When the police overstep their bounds, people whose rights have been violated can sue the offending officer in civil court. Criminal defendants, of course, can challenge the validity of a warrant, hoping to have any of the evidence excluded from consideration at trial. The concept of a warrant will come up again when we turn to the arrest process.

Arresting Suspects

The point of investigation, as we’ve already mentioned, is to locate suspects, specific individuals who were accused of committing a crime or who the police think may have committed the crime. Once a suspect has been identified and located, the police have to make an arrest. Just like searches, arrests usually need to be backed up by a warrant to remain lawful. Law enforcement officers will again turn to a judge, outlining the evidence that gives them probable cause to believe an individual has committed a crime. After the question of probable cause has been decided, the judge will issue an arrest warrant and the police gain the legal right to take their suspect into custody. Arrest warrants aren’t required in two circumstances:

  • when someone commits a felony or misdemeanor in the presence of an officer
  • when an officer has probable cause to believe that someone has committed a felony

In these cases, the police can go ahead and arrest the suspect without securing a warrant first. Warrants are always required when law enforcement officials hope to arrest someone on private property, unless exigent circumstances are present.

Filing Criminal Charges

Once a suspect has been taken into custody, the police must act quickly. Most states give law enforcement officials only 24 or 48 hours to charge a suspect with a crime or, alternatively, release them. Filing charges against a suspect grants the police and prosecutors additional time to keep the defendant in custody, develop their case and decide on the next steps.

Can Victims Press Charges?

Police don’t file criminal charges; prosecutors do (or United States Attorneys, in the case of federal cases).Victims don’t “press” charges, either; that’s a myth perpetuated by TV shows. Prosecuting attorneys review all of the evidence and information gathered by the police and decide whether or not a formal case should be brought against the defendant(s). In court, prosecutors have to prove their claims “beyond a reasonable doubt.” That’s a high standard to meet; all the evidence needs to point to the defendant(s).

To file charges, most prosecutors want to be very certain that their case will win out in court, but this is a decision that victims, in many cases, can influence. Many cases, for example, rely for their direct evidence on the eyewitness testimony of victims. Thus, a victim’s willingness to participate in criminal proceedings can sway a prosecutor’s hand, making them more likely to press charges. This logic cuts a number of ways. Sometimes, prosecutors will file charges and force a victim to testify, even though the victim has no interest in participating. In other cases, a prosecuting attorney will decide not to press charges, despite an extremely-cooperative witness. In any event, prosecutors always have the final say.

Criminal “Information”

To get the ball rolling, prosecutors can file a criminal “information” (often referred to as a “complaint”) in court. This is a document laying out a formal criminal charge. A limited number of states allow private citizens, including victims, to file criminal complaints or, alternatively, formally petition state prosecutors to bring criminal charges on their behalf, but these are rare circumstances. The vast majority of criminal cases begin when a prosecutor files an information, accusing the defendant of committing a crime.

Indictment By Grand Jury

Federal cases usually work differently. The Fifth Amendment to the Constitution grants defendants the right to indictment by a grand jury. Defendants, in other words, are allowed to request that a panel of ordinary citizens be convened to review the facts of a case before criminal charges are filed. Grand juries hear the evidence and decide whether or not the government has probable cause to believe that a crime was committed by the defendant.

The Fifth Amendment doesn’t extend to state or municipal criminal proceedings, but around half of the states have passed similar laws on their own, granting the right to indictment by grand jury to defendants in state criminal cases. An alternative approach, observed in several states (especially for felony crimes), provides defendants with the right to a “preliminary hearing.” In these proceedings, a judge will review the evidence presented by a prosecutor and make a finding on probable cause. Preliminary hearings usually happen after a criminal complaint has been filed.


Once criminal charges have been filed formally, the defendant will be arraigned. Some states refer to arraignment as a “preliminary hearing,” but in any event, the process is usually the same. The defendant is brought to a court room, where a judge will formally charge them with a crime. The defendant now has an opportunity to answer for the charges, pleading either guilty or not guilty.

Defendants in criminal cases always have a right to legal counsel. During arraignment, defendants with limited personal resources can ask the court to appoint counsel, a “public defender,” to represent their interests. This right is outlined in the Constitution’s Sixth Amendment, which reads in full:

“In all criminal prosecutions, the accused shall enjoy the right to a speedy and public trial, by an impartial jury of the State and district wherein the crime shall have been committed, which district shall have been previously ascertained by law, and to be informed of the nature and cause of the accusation; to be confronted with the witnesses against him; to have compulsory process for obtaining witnesses in his favor, and to have the Assistance of Counsel for his defence.”

The defendant’s attorney will be present at arraignment.

Setting Bail

Next, the judge will set bail. Criminal defendants have to put up some amount of money (or property) as a promise that they will participate in further court proceedings. Bail is returned to defendants who comply at all stages of the criminal justice process. Just as bail represents a promise, it can also be used as a tool. When the judge believes that a criminal defendant may try to go on the run, or represents a danger to the community, she can set the bail so high that the defendant has no way to pay it. Alternatively, judges can simply refuse to offer bail in the first place. In short, paying bail doesn’t guarantee a release from the community, although, in the cases of minor crimes, that’s often the outcome. Defendants with strong ties to the community, who have homes and jobs and families to think about, can be released on low bail amounts. Other defendants will be released on their own “recognizance” – without any bail.A

Negotiating A Plea Bargain

After criminal charges have been filed, a defendant’s attorney can begin to engage in negotiations. Faced by the uncertainty of a jury trial, many lawyers will try to hammer out a “plea bargain,” in which the defendant agrees to plead guilty to a lesser charge, or one charge among many, in exchange for a lower sentence. Prosecutors can’t guarantee that a lower sentence will be issued, but they can certainly recommend a sentence to the judge.

Under provisions of the Fifth and Fourteenth Amendment, criminal defendants have a right to “due process” – their legal rights must be respected at every step and, likewise, the procedures and rules adhered to must stay in the bounds of law at all times. Failing to disclose relevant evidence requested by a defense attorney is recognized as a violation of a defendant’s due process rights.

Defense attorneys have a right to review most of the evidence that prosecutors intend to present at trial. During the “discovery” phase of legal proceedings, attorneys can ask the government to disclose evidence, from police reports and witness statements to physical evidence seized during the investigation. Perhaps most important is “exculpatory” evidence – evidence that, upon reasonable scrutiny, would tend to exonerate the defendant of guilt. The “Brady Rule,” named in reference to a 1963 US Supreme Court case, requires that prosecutors disclose all evidence that would be favorable to the defendant.

How strong is the government’s case? Weak cases may convince a lawyer to try their luck in court. When the government has a strong case, on the other hand, defense attorneys are more likely to pursue serious plea negotiations. If a plea bargain is reached, the defendant will be brought into court to plead guilty before a judge. In some jurisdictions, defendants have to demonstrate, in at least a minimal sense, that they are pleading to a crime they did, in fact, commit. This step is known as providing a “factual basis for the plea.”

The Criminal Trial

When a plea agreement can’t be reached, criminal proceedings move to the trial phase.

We usually think of criminal trials being held before a jury, but in reality, the legal right to a trial by jury usually only applies for crimes that are punishable with at least six months of imprisonment. Crimes that entail lesser sentences can be heard before a judge, rather than a jury. This is known as a “bench trial.”

Some defendants actually choose to have their cases heard by a judge alone. Bench trials are most common when the defendant’s defense relies on technical legal arguments that would probably soar over the heads of ordinary jurors. Bench trials are also common when the facts of a case are so extreme or horrifying that the defendant fears a jury will be unable to scrutinize the evidence objectively.

Jurors are “triers of fact” – they attempt to figure out what actually happened, analyzing the evidence to determine whether or not the crime happened in line with the prosecution’s argument. Judges, on the other hand, are “triers of law” – they figure out how the law should be applied and instruct jurors accordingly. In bench trials, both of these roles, trier of fact and law, devolve to a judge.

Jury Selection

Both prosecutors and defendants have a right to screen out potential jurors who won’t be able to view the case’s evidence objectively. This stage of the trial is known as “voir dire,” an odd derivation of the Latin phrase verum dicere – to speak the truth. During voir dire, each juror will be questioned about their background and opinions. Jurors can be dismissed because they already know about the case’s details, have a relationship with any of the parties involved or have strong opinions about issues that will become relevant at trial.

In most cases, an attorney has to give a good reason for dismissing a juror, although each side will be given a limited number of “peremptory challenges,” allowing them to dismiss a few jurors without any explanation at all.

Peremptory challenges are not without their pitfalls, at least from the perspective of justice. In the past, attorneys would frequently use their peremptory challenges to dismiss solely black jurors, leaving an all-white jury to try cases that often involved black defendants.  In 1986, the US Supreme Court decided Batson v. Kentucky, holding that peremptory challenges could not be used to dismiss jurors solely based on their race, but this is a pernicious form of discrimination and difficult to eliminate. Today, courts continue to find that juries have been inappropriately selected on the basis of race.

At Trial

Defendants have the right to a “speedy and public trial.” As a result, defendants can sometimes force the government to move quickly, by arguing that their right to a speedy trial is being violated. By the same logic, defendants can also waive their right to a speedy trial (granted by the Sixth Amendment), giving their attorney more time to prepare a viable defense.

Once the trial has begun, both sides of the case have an opportunity to present evidence, call witnesses and pursue rational arguments in favor of their interpretation of events. A defendant has the same rights as the prosecution and can present exculpatory evidence and question witnesses to prove their innocence. Defendants also have the right to “confront” witnesses called by the prosecution during “cross-examination.” Accused offenders can try to poke holes in a witness’ story, undermine their credibility or question the credentials of an expert.

After the evidence has been presented, the judge will formally “charge” the jury to perform their obligations and provide guidance on relevant legal issues. The prosecution and defense have a final opportunity to sum up their reasoning during closing arguments. The jurors then leave the courtroom, withdrawing to a secret location to deliberate amongst themselves. In their deliberations, jurors will reexamine the facts of the case, argue over different interpretations and, ultimately, attempt to form a consensus. They can ask to hear witness statements again or request further clarifications from the judge on matters of law, although defendants and prosecutors have the right to dispute these requests.

Ideally, jury deliberations lead to a unanimous verdict, either guilty or not guilty. Criminal trials require unanimity; all 12 jurors must agree on the verdict. When a unanimous verdict has been reached, the jurors return to the courtroom and a “foreperson,” who has been selected to speak for the jury’s 12 members, will announce the verdict. When the jurors haven’t been able to reach an agreement, the foreperson will announce that the jury is “deadlocked.” Colloquially, a jury that can’t agree is called a “hung” jury. At this point the judge has two options:

  • Declare a mistrial – court proceedings are terminated without a judgment, leaving open the opportunity for a new trial
  • Tell the jury to keep trying

Most judges want a jury to resume deliberations at least once, but, if this second attempt is unsuccessful, a mistrial becomes more likely.

After The Verdict

Naturally, what happens after a verdict is rendered depends largely on the verdict. In the case of not guilty verdicts, defendants will be released as soon as possible, unless they are being held on charges that were not considered in the trial. After a guilty verdict, on the other hand, the criminal justice process proceeds to sentencing, which takes place during a separate hearing. Guilty verdicts can be appealed to a higher (“appellate”) court, at which point the defendant can argue that their conviction was obtained improperly.

Sentences come in a range of flavors, but most rely on the same basic categories of punishment:

  • Imprisonment
  • Probation – release from custody for a period of supervision
  • Fines
  • Community Service
  • Capital punishment – the death sentence

Judges determine sentences in the vast majority of cases. Juries usually aren’t involved. Several states make an exception in the case of the death penalty; in these jurisdictions, a judge is not allowed to sentence the defendant to death unless a jury endorses capital punishment over a life sentence. In some cases, a state’s criminal code will spell out an acceptable range of sentences for a certain crime. The federal justice system also has its own “sentencing guidelines” to steer the decisions of federal judges. While sentencing guidelines often give judges a fairly wide latitude, and some are entirely optional, most judges today stay within the bounds prescribed by law.