Federal criminal jurisdiction is limited. Congress can criminalize conduct only where it has constitutional authority — most often the commerce power, but also the taxing power, the postal power, authority over federal property and federal programs, and authority over immigration, customs, and interstate and foreign affairs. The result is that most ordinary crime is state crime, and the federal system handles a comparatively narrow slice with a disproportionate share of resources.

Who brings the case

A state case is brought by a district attorney, state's attorney, or attorney general, typically investigated by municipal police or a county sheriff's office. A federal case is brought by a United States Attorney's Office or a litigating division of the Justice Department, investigated by the FBI, DEA, ATF, IRS Criminal Investigation, Homeland Security Investigations, the Postal Inspection Service, or an inspector general's office.

The resource asymmetry is the practical difference. Federal investigations often run for years before charges, with grand jury subpoena power, wiretap authority, forensic accounting, and cooperating witnesses developed over time. By the time a federal indictment issues, the case is usually built. State charges are frequently filed within days of an arrest, and the investigation continues afterward.

Procedure

  • Charging. Federal felonies require a grand jury indictment unless the defendant waives it. Many states permit prosecution by information after a preliminary hearing, which gives the defense an early adversarial testing of probable cause that the federal system does not.
  • Pretrial release. The federal Bail Reform Act asks whether conditions can reasonably assure appearance and safety, and uses detention rather than money as the primary tool, with presumptions of detention in certain categories. Most state systems still run on bail schedules and money bond, though that varies widely.
  • Discovery. Federal discovery under Rule 16 is comparatively narrow, and witness statements often arrive close to trial under the Jencks Act. Several states have broader open-file discovery, including witness lists and statements well before trial.
  • Juries. Federal juries are twelve members and must be unanimous, drawn from an entire district, which is often geographically and demographically broader than a single county.
  • Speed. The federal Speedy Trial Act imposes a 70-day clock subject to extensive exclusions. State timelines vary and are frequently longer in practice for serious cases.

Sentencing, and the part people underestimate

This is where the systems diverge most. Federal sentences are calculated under the advisory guidelines and imposed by the judge under 18 U.S.C. § 3553(a). Federal parole was abolished for offenses committed after November 1, 1987. A federal sentence is served, less good conduct time capped at 54 days per year under 18 U.S.C. § 3624(b) and any earned time credits available under the First Step Act. A ten-year federal sentence is roughly an eight-and-a-half-year sentence.

Many state systems retain parole boards, day-for-day credit schemes, or aggressive good-time formulas under which the served portion of a nominal sentence is far lower. Many state systems also offer deferred adjudication, pretrial diversion, and expunction pathways that have no general federal equivalent. Federal diversion exists but is comparatively rare, and there is no general federal expungement statute.

Mandatory minimums are present in both systems but are especially consequential federally in drug and firearms cases, where quantity thresholds under 21 U.S.C. § 841 and the stacking provisions of 18 U.S.C. § 924(c) can produce decades of exposure that no judicial discretion can reach absent a safety valve or a government motion.

Overlapping jurisdiction and successive prosecution

Where conduct violates both federal and state law, either sovereign may prosecute. Under the dual sovereignty doctrine, reaffirmed in Gamble v. United States (2019), the Double Jeopardy Clause does not bar successive prosecutions by the state and the federal government for the same conduct. Justice Department policy — the Petite policy — discourages a federal prosecution following a state one absent a substantial unvindicated federal interest and approval from Main Justice, but it is internal policy, not an enforceable right.

What the difference means for a defendant

Being charged federally does not automatically mean a longer sentence; a serious violent offense may carry more exposure in state court. What it reliably means is a system with a more developed pre-charge investigation, fewer early opportunities to test the government's proof, a structured and heavily anchored sentencing regime, no parole, and a professional prosecuting office with a very high conviction rate. Those structural features, not the label, are what change.