A district attorney is the chief local prosecutor who represents the state in criminal cases, and what a district attorney does covers everything from deciding whether someone gets charged, to negotiating plea deals, to trying cases before a jury, to recommending sentences and advocating for victims. The DA runs an office of assistant prosecutors who handle this work across a county or judicial district, enforcing state criminal law on behalf of the public.
Deciding Who Gets Charged
The single most powerful tool a district attorney holds is the discretion to decide whether someone is charged with a crime at all. After police make an arrest and hand over their evidence, a prosecutor reviews that file and decides whether to move forward. The question isn’t just whether a crime probably happened. Prosecutors weigh the strength of the evidence, whether key proof would survive legal challenges, how serious the alleged offense is, and whether the suspect has prior convictions.
Resources shape these choices too. Every DA’s office has more potential cases than it can handle, so prosecutors prioritize. A violent felony with a cooperative witness almost always jumps ahead of a minor property crime with shaky proof. The DA can also decline charges entirely, even when police believe they’ve built a solid case, if prosecution doesn’t serve the public interest. That gatekeeping authority is a large part of why the office is one of the most powerful in the criminal justice system.
Guiding Investigations
The DA’s involvement often begins well before an arrest. Prosecutors advise detectives during investigations so evidence is gathered in ways that will hold up in court. A confession taken without proper warnings or a search done without legal authority can sink an otherwise strong case, which is why early guidance matters.
Prosecutors also draft applications for search warrants, which a judge must approve after finding probable cause under the Fourth Amendment.1Constitution Annotated. Amdt4.5.3 Probable Cause Requirement They help secure subpoenas for witnesses and records. For felony cases, the DA’s office may present evidence to a grand jury, a group of citizens who review the evidence in a closed proceeding and decide whether to formally charge the suspect through an indictment.2United States Department of Justice. Charging Federal law requires a grand jury for all felonies; states vary on when one must be convened.
Turning Over Evidence to the Defense
Before trial, prosecutors are legally required to share relevant evidence with the defense. Under federal rules, the government must turn over the defendant’s own statements, prior criminal record, documents and physical evidence it plans to use at trial, and reports from scientific tests or expert examinations.3Legal Information Institute. Rule 16 – Discovery and Inspection State rules differ in detail but follow the same principle.
The most important disclosure rule comes from the Supreme Court’s 1963 decision in Brady v. Maryland. The Court held that prosecutors must hand over any evidence favorable to the defendant that is material to guilt or punishment, whether or not the defense asks for it.4Justia US Supreme Court. Brady v Maryland, 373 US 83 (1963) That includes evidence that could undermine a prosecution witness’s credibility or suggest the defendant didn’t commit the crime. The duty applies whether the prosecutor withholds the evidence intentionally or by accident.5Legal Information Institute. Brady Rule Violations are notoriously hard to catch, since the defense by definition doesn’t know what it hasn’t been shown, and they often surface only after a conviction.
Negotiating Plea Deals
Trials get the attention, but plea bargaining is where most criminal cases end. Roughly 98 percent of federal cases and a similar share of state cases are resolved through negotiated guilty pleas rather than trial. In a typical deal, the defendant pleads guilty, often to a reduced charge or in exchange for a lighter sentencing recommendation from the prosecutor.6Legal Information Institute. Plea Bargain The DA’s office negotiates these agreements with the defense attorney, and a judge must approve the final deal.
Plea deals serve practical purposes on both sides. Prosecutors secure a conviction without the time, expense, and uncertainty of trial. Defendants avoid the risk of a harsher sentence after a jury verdict. Critics argue the system pressures innocent people to plead guilty, especially when they’re held in jail pretrial and a plea means going home. Supporters say that without plea deals, courts would grind to a halt. Either way, the DA’s ability to set the terms of plea offers is one of the most consequential parts of the job.
Trying Cases in Court
When a case does go to trial, the prosecutor’s job is to prove the defendant’s guilt beyond a reasonable doubt, the highest standard of proof in the legal system.7Legal Information Institute. Beyond a Reasonable Doubt That means delivering opening and closing arguments, calling witnesses, introducing physical evidence, presenting expert testimony, and cross-examining the defense’s witnesses. The process is adversarial, with the defense attorney challenging every piece of evidence and every argument the prosecution puts forward.
Recommending Sentences and Representing Victims
After a guilty plea or conviction, the DA’s office participates in sentencing. Prosecutors make a sentencing recommendation to the judge based on the facts of the case, the defendant’s criminal history, and applicable sentencing guidelines. The judge has the final say, but the recommendation carries real weight.
Prosecutors also advocate for crime victims throughout the process. Federal law gives victims specific rights, including timely notice of court proceedings, the right to be heard at sentencing, the right to confer with the prosecutor, and the right to restitution.8GovInfo. 18 USC 3771 – Crime Victims Rights Most states have adopted parallel protections. In practice, DA offices typically employ victim-witness coordinators who keep victims informed about court dates, help prepare impact statements for sentencing, and connect them with support services.9United States Department of Justice. Victim Impact Statements
When a defendant has prior felony convictions, the prosecutor can seek sentencing enhancements, which increase punishment based on criminal history. The procedure typically requires the prosecutor to file a formal notice identifying the prior convictions before trial or before a guilty plea is entered.10Office of the Law Revision Counsel. 21 USC 851 – Proceedings to Establish Prior Convictions These enhancements can dramatically increase prison time, giving prosecutors significant leverage during plea negotiations.
Handling Appeals and Reviewing Old Convictions
The work doesn’t end at conviction. If a defendant appeals, the prosecutor’s office, or in some states the attorney general’s office, defends the conviction in appellate court. That means filing written briefs arguing the trial was fair, the evidence was sufficient, and no legal errors tainted the result. In post-conviction proceedings where a defendant claims newly discovered evidence or a constitutional violation, the prosecutor responds to those challenges.
A growing number of DA offices have also created Conviction Integrity Units, dedicated teams that proactively review cases where a wrongful conviction may have occurred. These units investigate claims of innocence, reexamine evidence using modern forensic techniques, and, when warranted, move to vacate convictions.
Running Diversion Programs
Not every case has to end with a conviction and a sentence. Many DA offices run or participate in pretrial diversion programs that route certain defendants, often those charged with low-level drug offenses, mental health-related crimes, or first-time nonviolent offenses, into treatment, community service, or supervision instead of the traditional court process.11United States Department of Justice. Justice Manual 9-22.000 – Pretrial Diversion Program If the defendant completes the program, charges are typically dismissed.
The DA’s office decides who qualifies, which makes the prosecutor the gatekeeper for these programs just as they are for traditional charges. Drug courts, mental health courts, and veterans treatment courts all depend on the prosecutor agreeing to participate. A DA who embraces diversion for nonviolent offenders will produce very different outcomes than one who insists on prosecution across the board.
How a District Attorney Differs From a U.S. Attorney
People often confuse the two, but they operate in different systems. A district attorney is a local official, usually elected, who prosecutes violations of state law in state courts. A U.S. Attorney is a federal official, appointed by the President, who prosecutes violations of federal law in federal courts.12United States Department of Justice. Frequently Asked Questions
The types of crimes they handle reflect that split. DAs prosecute the cases most people picture when they hear the word “crime”: assault, robbery, burglary, DUI, drug possession, murder. U.S. Attorneys focus on offenses like tax fraud, wire fraud, bank robbery, drug trafficking, immigration violations, and federal civil rights crimes. Some conduct, such as bank robbery, violates both state and federal law, and in those situations the offices coordinate on which system will handle the case.
How Someone Becomes a District Attorney
In 47 states, the district attorney is elected by voters in the county or district, which makes the position directly accountable to the local community. Only Alaska, Connecticut, and New Jersey appoint their chief local prosecutors. Most elected DAs serve four-year terms, though Alabama, Kentucky, and Louisiana use six-year terms, and Tennessee’s prosecutors serve eight-year terms.
To run, a candidate must be a licensed attorney admitted to the state bar. Most competitive candidates have spent years as assistant district attorneys, building trial experience and name recognition in the local legal community. Because the DA is elected, the officeholder’s priorities, which crimes to focus on, how aggressively to seek maximum sentences, whether to expand diversion programs, are ultimately shaped by what voters in that community want.