How a Federal Criminal Case Works: From Grand Jury to Prison
Key takeaways
- Federal crimes are investigated by agencies such as the FBI and DEA and prosecuted by 94 U.S. attorneys' offices in the Justice Department.
- Felony charges must be approved by a grand jury of 16 to 23 citizens, meeting in secret, which almost always indicts.
- About 90 percent of federal defendants plead guilty, and only about 2 percent go to trial.
- Judges calculate sentences under advisory guidelines but must follow mandatory minimums set by Congress, and there is no federal parole.
- About 155,000 people are held by the Federal Bureau of Prisons, and the President can pardon or commute federal sentences.
- The federal death penalty was revived in 2025 after a moratorium and mass commutations, with 44 death cases authorized by April 2026.
Most crimes are prosecuted by states, but federal cases, from drug trafficking and fraud to terrorism and public corruption, follow their own rules and run through the national court system. They move through a series of steps, each with its own officials and constitutional protections.
This guide follows a federal case from investigation to charges, plea or trial, sentencing, and prison, and sets out the debates over plea bargaining, sentencing, the death penalty, and the power of prosecutors.
The Federal Bureau of Prisons holds about 155,000 people in prisons, camps, and contract facilities. Defendants can appeal convictions and sentences to the regional courts of appeals and then ask the Supreme Court to hear the case, which it rarely does. The President has unlimited power to pardon federal crimes or commute sentences, with applications reviewed by the Office of the Pardon Attorney, though recent Presidents have also granted clemency outside that process.
The Fifth Amendment requires that serious federal charges be approved by a grand jury, 16 to 23 citizens who hear the prosecutor's evidence in secret and indict if at least 12 find probable cause. Grand juries almost always indict, though several declined in high-profile cases in 2025. After arrest, a defendant appears before a magistrate judge, is told of the charges, and is assigned a federal public defender or other appointed lawyer if needed. Under the Bail Reform Act of 1984, a judge decides whether to release the defendant before trial or hold the person as a flight risk or danger, with pretrial services officers making recommendations.
About 90 percent of federal defendants plead guilty, usually under agreements in which prosecutors drop charges or recommend a lower sentence, and about 8 percent have charges dismissed. Only about 2 percent go to trial, before a jury of 12 that must reach a unanimous verdict, and most of those are convicted. The Speedy Trial Act generally requires trial within 70 days of indictment, though delays are common. Defendants have the right to counsel, to confront witnesses, and to see evidence that could help them. Critics say the gap between plea offers and post-trial sentences pressures even innocent people to plead guilty.
A federal case usually begins with an investigation by an agency such as the FBI, the Drug Enforcement Administration, Homeland Security Investigations, or IRS Criminal Investigation, often working with state and local police. Agents gather evidence through interviews, subpoenas, and search warrants approved by judges. Decisions to charge rest with the 94 U.S. attorneys' offices and divisions of the Justice Department, which follow department policies on when to bring charges and which ones. Federal prosecutors bring roughly 70,000 to 80,000 criminal cases a year, a small share of all criminal cases in the country, most of which are handled by states.
About 60 federal crimes carry a possible death sentence, which prosecutors may seek only with the Attorney General's approval. After 13 federal executions in 2020 and 2021, a moratorium, and the commutation of 37 of 40 death sentences in December 2024, the Justice Department lifted the moratorium in February 2025, authorized seeking death in 44 cases by April 2026, and added the firing squad as a method. Broader debates concern overcriminalization, mandatory minimums, plea pressure, racial disparities, and the independence of prosecutors, with critics in 2025 and 2026 accusing the department of pursuing political opponents and supporters saying it was ending a double standard in past prosecutions.
After a conviction, a probation officer prepares a presentence report, and the judge calculates a range under the federal sentencing guidelines, which combine the seriousness of the crime with the defendant's record. The guidelines have been advisory since 2005, but mandatory minimums set by Congress, especially for drug and gun crimes, still bind judges unless a defendant qualifies for an exception. There is no federal parole, so prisoners serve at least about 85 percent of their sentences, followed by a period of supervised release. The First Step Act of 2018 eased some mandatory minimums and lets prisoners earn credits for rehabilitation programs.
See who investigates in federal law enforcement agencies, the rights involved in the Bill of Rights, or the last step in presidential pardons explained.