In a criminal case, a state prosecutor is the government lawyer who decides whether to bring charges, builds the case against the accused, negotiates plea agreements, tries the case in court if it does not settle, argues for a sentence after a conviction, and defends that conviction on appeal. The role runs from the moment police hand over an arrest file to the final appellate ruling, and at every step the prosecutor is bound by a duty the Supreme Court has described as making sure “justice shall be done,” not simply winning.1Justia. Berger v. United States, 295 U.S. 78 (1935)
That duty has teeth. Professional conduct rules forbid a prosecutor from pursuing charges they know lack probable cause and require timely disclosure of evidence that could help the defense, including anything that weakens the government’s case or might reduce a sentence.2American Bar Association. Rule 3.8 – Special Responsibilities of a Prosecutor A prosecutor who hides favorable evidence or files charges without legal basis isn’t just doing a poor job; they are violating binding obligations.
Deciding Whether to Charge
After an arrest, the prosecutor reviews what the police gathered and decides whether the case moves forward. The threshold question is probable cause: whether the facts would lead a reasonable person to believe a crime occurred and the suspect committed it.3Legal Information Institute. Probable Cause It is a much lower bar than what is needed to convict, and it does not require the prosecutor to think the suspect is probably guilty.4Constitution Annotated. Amdt4.5.3 Probable Cause Requirement
Even when probable cause is obvious, the prosecutor is not required to file. This authority is called prosecutorial discretion, and it is one of the most consequential powers in the system. The prosecutor weighs the strength of the evidence, the seriousness of the offense, the suspect’s record, the impact on the victim, and whether charging serves the public interest. The possible outcomes are charges, referral to an alternative program, or declining the case outright.
A prosecutor can also drop charges after filing. That voluntary dismissal is not an acquittal. Because nothing was decided on the merits, the government can refile later if new evidence surfaces.
Diversion Instead of Prosecution
For some defendants, the prosecutor’s choice is a diversion program rather than a conviction. The defendant completes requirements like community service, counseling, drug treatment, or classes, and if they succeed the charges are dismissed or reduced.5U.S. Department of Justice. Justice Manual 9-22.000 – Pretrial Diversion Program Diversion is usually limited to nonviolent offenses and people without serious criminal histories. Cases involving serious bodily injury, firearms, sexual abuse, or child exploitation are typically excluded. Many jurisdictions also run specialized drug, veterans, and mental health courts where the prosecutor collaborates with judges and treatment providers.
Filing Charges and Pre-Trial Work
Charges reach the court in one of two ways. The prosecutor can file an “information,” a signed written statement laying out the essential facts of the offense, or present the case to a grand jury, which decides whether to return an “indictment.”6Legal Information Institute. Federal Rules of Criminal Procedure Rule 7 – The Indictment and the Information Many jurisdictions require a grand jury indictment for serious felonies.
Preliminary Hearings
Before trial, a judge may hold a preliminary hearing to decide whether the evidence justifies going further. The prosecutor puts on witnesses and the judge rules on whether probable cause supports the charges.7U.S. Department of Justice. Preliminary Hearing If the evidence falls short, the charges are dismissed, though the government can potentially refile with stronger proof. Unlike a grand jury proceeding, the defendant and defense attorney are present at a preliminary hearing and can cross-examine the prosecution’s witnesses. When a defendant is in custody, the hearing generally must occur within 14 days of the initial court appearance.
Bail
The prosecutor also tells the court what it thinks should happen with the defendant before trial. When arguing for higher bail or pretrial detention, the prosecutor presents the defendant’s flight risk, criminal history, and any danger to the community. The judge decides, but the recommendation carries real weight in violent cases or where the defendant has prior failures to appear.
Discovery and the Brady Duty
A large share of pre-trial work is exchanging evidence with the defense. Under federal rules the defense can request the defendant’s own statements, prior record, documents and physical evidence the government intends to use, and forensic test results.8Legal Information Institute. Federal Rules of Criminal Procedure Rule 16 – Discovery and Inspection State rules vary but generally follow a similar pattern.
On top of that, the prosecutor has a constitutional obligation from Brady v. Maryland to turn over evidence favorable to the accused when it is material to guilt or punishment.9Justia. Brady v. Maryland, 373 U.S. 83 (1963) A witness whose story changed, inconclusive lab results, anything that casts doubt on guilt or supports a lower sentence has to be disclosed. The duty applies whether or not the defense asks, and whether or not the prosecutor acted in good faith.10Legal Information Institute. Brady Rule When a court finds a Brady violation, the typical remedy is overturning the conviction; if it comes out during trial, the judge can declare a mistrial or block the tainted evidence.
The Speedy Trial Clock
Prosecutors do not have unlimited time. The Sixth Amendment guarantees a speedy trial, and courts weigh the length of any delay, the government’s reasons, whether the defendant objected, and the harm caused.11Constitution Annotated. Amdt6.2.1 Overview of Right to a Speedy Trial Federal law adds hard deadlines: an indictment or information within 30 days of arrest, and trial within 70 days of charging or first court appearance, whichever is later.12Office of the Law Revision Counsel. 18 USC 3161 – Time Limits and Exclusions Most states have their own versions. Pretrial motions and certain continuances pause the clock, but the pressure to move cases is real.
Plea Bargaining
Between 90 and 95 percent of criminal cases in state and federal courts end in a plea rather than a trial.13Bureau of Justice Assistance. Plea and Charge Bargaining Research Summary The prosecutor drives these negotiations. They size up the evidence, think about how a jury might react, consider the resources a trial would consume, and factor in what serves the victim and the public. A weak case with shaky witnesses pushes toward a more generous offer; a strong case gives the prosecutor leverage to demand something closer to the maximum. The defense negotiates from the other side, and any deal still has to be accepted by the judge, who is not bound by the prosecutor’s sentencing recommendation.
Plea bargaining draws criticism. Defendants facing serious charges can feel pressured to plead even when they maintain innocence, simply to avoid a much harsher sentence after trial. From the prosecutor’s side, a plea produces a certain outcome, spares victims from testifying, and frees up resources for cases that need a full trial.
Taking the Case to Trial
If a case does not settle, the prosecutor carries the burden of proving every element of the charged crime beyond a reasonable doubt, the highest standard of proof in the legal system.14Legal Information Institute. Beyond a Reasonable Doubt The defendant has to prove nothing. If the prosecutor falls short on even one element, the jury must acquit.
Trial starts with jury selection, where the prosecutor questions potential jurors for bias. Both sides can remove jurors for cause when bias is apparent, and each side has a limited number of strikes they can use without stating a reason. After the jury is seated the prosecutor delivers an opening statement, then presents the case-in-chief: calling witnesses, introducing documents and physical evidence, and walking jurors through the chain of events. For each piece of physical evidence the prosecutor has to lay a foundation showing the item is what they claim it is and has not been tampered with, which usually means calling the officer or technician who collected or analyzed it.
The prosecutor also cross-examines any witnesses the defense calls, probing inconsistencies and credibility. After both sides rest, the prosecutor delivers a closing argument that ties the evidence to each legal element of the charge.
Sentencing, Restitution, and Victims
A guilty verdict or plea does not end the prosecutor’s role. At sentencing the prosecutor recommends a penalty reflecting the severity of the offense, the defendant’s record, and the harm to victims. Prosecutors can also argue for sentence enhancements when the defendant qualifies under habitual-offender laws or when aggravating factors like firearm use or a vulnerable victim apply. These enhancements can add significant time.
Restitution
Federal law requires courts to order restitution for victims of many crimes, covering losses like property damage, medical expenses, lost income, therapy costs, and funeral expenses where applicable.15GovInfo. 18 USC 3663A – Mandatory Restitution to Victims of Certain Crimes The prosecutor consults with victims, compiles documentation of their losses, and presents those figures to the court. The order must reflect the full amount of each victim’s losses regardless of the defendant’s ability to pay. Most states have similar requirements, and the prosecutor is typically the one making sure the court has accurate loss information.
Victim Rights
Federal law also guarantees crime victims specific rights that the prosecutor is expected to help enforce: reasonable notice of court proceedings, the right to attend them, the right to be heard at release, plea, and sentencing hearings, and the right to confer with the prosecuting attorney.16GovInfo. 18 USC 3771 – Crime Victims Rights Victims must be informed about plea bargains or deferred prosecution agreements before they are finalized. In practice the prosecutor’s office is the victim’s main point of contact: notifying them of hearings, explaining what is happening, and facilitating victim impact statements at sentencing. Every state has its own version of these protections.
Defending the Conviction on Appeal
If a convicted defendant appeals, the prosecutor’s office responds. The defense argues legal errors affected the outcome; common grounds include improper admission or exclusion of evidence, flawed jury instructions, and prosecutorial misconduct.17American Bar Association. ABA Standards for Criminal Justice – Criminal Appeals The prosecutor files written briefs defending the trial and presents oral argument to the appellate court, generally trying to convince the court that any errors either did not occur or were harmless. If the appellate court finds a significant error, it can overturn the conviction, order a new trial, or modify the sentence, and the prosecutor then decides whether to retry, negotiate a plea, or let the matter end. In high-profile cases a single conviction may be defended through multiple rounds of appeal up to the state supreme court.
What a Prosecutor Cannot Do, and When They Can Be Held Accountable
Professional rules spell out what is off-limits: a prosecutor cannot pursue charges without probable cause, cannot withhold favorable evidence, and cannot make public statements likely to inflame opinion against the accused.2American Bar Association. Rule 3.8 – Special Responsibilities of a Prosecutor Violating these rules can lead to professional discipline ranging from a private reprimand to suspension or disbarment, and courts that catch misconduct can declare a mistrial, suppress evidence, dismiss charges, or overturn a conviction.
Civil lawsuits are a different story. The Supreme Court held in 1976 that prosecutors have absolute immunity from civil suits for actions taken while initiating and presenting criminal cases.18Justia. Imbler v. Pachtman, 424 U.S. 409 (1976) A defendant who was wrongly prosecuted generally cannot sue the prosecutor for money damages, even where the prosecutor acted recklessly or in bad faith. The immunity covers only advocacy-related work, not conduct where the prosecutor is acting as an investigator or administrator, but within that advocacy sphere it is broad. The practical result is that the main checks on a prosecutor are internal ethics enforcement and the courts themselves.