Today’s subject may seem a bit esoteric, yet it’s vital to understanding the US criminal justice system. The subject is fragmentation.

Most countries have a national system of criminal justice. A single set of laws, police, courts, and corrections, all administered at the federal level. Oh, but not us. We can blame the English, who brought with them a complicated system built from their history as many tiny and diverse kingdoms unwillingly united under the Norman Conquest. We can blame our own history too—separate colonies, a long and shifting frontier, and varying views of the role of federalism. What we ended up with was a tangle.

Let’s look at law enforcement, for example.

Suppose the police were called to the street outside my home here in California. Those police might be my local city police. Because I live near a university campus, they might also be campus police (a state agency). They might be sheriff’s deputies—a county agency. They might work for any one of a variety of specialized state agencies, including highway patrol, fish and wildlife, park service, firearms, gambling patrol, department of motor vehicles, and many more. They might work for one of many federal law enforcement agencies. FBI. ATF. DEA. Customs. US Marshals. FAA. Secret Service. And lots, lots more. Under very specific circumstances, that cop outside my door may even work for the international agency, INTERPOL.

There are currently over 17,000 separate police agencies in the United States, with roughly two-thirds of them being municipal (city) police departments.

And that’s just the police! We also have courts at the federal and state (and sometimes local) level. We have laws at varying levels too. And corrections may be local, state, or federal. And you know what? Each agency has different rules and policies.

This is the reason behind my frequent warning to check with your relevant jurisdiction before writing. Just because one agency does things a certain way or you’ve seen it done a particular way on TV doesn’t mean that’s how it’s done in your setting. I’ve seen authors mess this up many times. It throws me out of the story and indicates sloppy research.

Such a complex situation has bad points and good. On the downside, it leads to inconsistencies and misunderstandings. It sometimes causes friction between members of different agencies. Sometimes agencies may even have trouble communicating with one another due to different technology or policies or resources. Or plain old stubbornness.

I should note, though, that contrary to what you’ve seen in movies, agencies generally cooperate with each other. The other day, a morning car wreck happened along a busy street near the university, junior high, high school, and elementary school. And it happened right when everyone was dropping kids off or going to work. My city police responded, but so did campus police and the highway patrol (which has jurisdiction on all public byways), and they worked together to deal with the problem. Similarly, many of the small towns in my area have limited resources for dealing with homicides, which are rare. So when one does occur, they have an agreement that allows them to call in homicide detectives from our county’s largest city.

Fragmentation has a major upside, which is probably the main reason it has continued so long here. That’s the possibility of local control. Washington, DC, doesn’t know what’s going on in my small city and mostly doesn’t care. Solutions and policies crafted in Washington may not be very effective in California’s Central Valley. But our local police can be very responsive to our particular concerns. They know, for instance, that traffic becomes problematic during the first couple weeks of the school year, and they increase patrols near schools (One particular motorcycle cop must write dozens of tickets daily. I always see him pulling people over.).

Now, some could argue that federal systems could also understand local issues if they had local administrative offices. But if my community is unhappy with our police, we can talk to our city council members and have them put pressure on the chief to fix things—or be fired. That couldn’t happen as easily with a national system. Of course, local control can be a serious problem too, depending on who’s doing the controlling. Historically, for example, some local police departments not only didn’t interfere with violence and intimidation of African American residents but may even have encouraged and participated in those acts. This has sometimes resulted in federal agencies stepping in.

Fragmentation can also be a challenge or a boon to writers. As I’ve said (many, many times!) it requires careful, specific research. Yet it can also be a source of wonderful plot points. You know…. Jaded federal agent from the Big City comes to the Small Town to investigate a crime. Romance (or dastardly deeds, or humor) ensues. Or hapless hero assumes what’s legal back home is also legal on vacation, but it’s not. Romance or dastardly deeds or humor ensue.