Jim winced when Agent Simon tightened the handcuffs. “Ow!”
“You’re not going to escape this time,” Agent Simon growled.
“Yeah, yeah. Look, I don’t know why you’re making such a big deal out of this. Nothing happened. I just sent out some letters is all.”
Agent Simon shook her head. “Sent out letters telling people the IRS had audited them and they’d face huge fines if they didn’t send you cash. That’s mail fraud, bub.”
Pretending nonchalance, Jim awkwardly shrugged. “So what? You don’t gotta make a federal case out of it.”
Oh yes, she does.
The vast majority of crimes in the US are handled at the local and state level. Local police arrest the suspects, state courts try them, and—if the suspects are incarcerated—they’re held in local jails or state prisons.
But sometimes the feds step in too. In these cases, the people are arrested by federal police (more on them in a moment), tried in federal court, and incarcerated in federal facilities. When does this happen?
- When the alleged crime occurs in Washington, DC. That’s because the District of Columbia is, by design, outside of any state and under federal authority.
- When the alleged crime occurs on federal property or on an Indian reservation.
- When the alleged acts violate federal law.
Compared to the states, there aren’t many federal criminal laws. Many of them involve acts that affect interstate commerce, such as bank robbery or Jim’s mail fraud. The most commonly prosecuted federal offenses are drug crimes and immigration offenses. Few people are prosecuted at the federal level for violent crimes.
Although most people think of the FBI when they think about federal law enforcement, there are actually many federal law enforcement agencies, each with a specific charge. These include the DEA (drugs), IRS (taxes), ATF (alcohol, tobacco, firearms, and explosives), ICE (immigration and customs), U.S. Marshals (fugitives), air marshals, Secret Service, and more. There’s a good chance Agent Simon is with the postal inspectors.
Sometimes federal agencies may come in to assist local agencies when a crime crosses several local jurisdictions or when the investigation requires specialized knowledge. A common example of this in fiction involves serial killers. And yes, sometimes there’s friction between the agencies involved, just like you’ve seen in movies, but often the agencies cooperate fully.
Incidentally, despite double jeopardy protections, a person can be prosecuted by a state and the feds for the same crime. This is because of something called the dual sovereignty doctrine. You can read more about that here.