If you write mysteries or suspense novels, one of your characters might very well go missing. Now, maybe nobody notices or nobody cares. That may be a plot point in itself. But what if someone’s looking for the guy? Then they might file a missing persons report.

Here are a few things you should know about that process.

First, the name itself: missing persons report. It’s grammatically awkward. By rights, it should be missing person or missing person’s report. This was a point of discussion with the editor for one of my recent books. But while she had the grammar correct, legal agencies use the specific term missing persons–without an apostrophe. Here’s a relevant FBI page, for example. I haven’t been able to dig up any information on the origin of the term. Bad translation from French, maybe. But there it is.

The next thing you need to know is that—quelle surprise!—rules and policies vary by jurisdiction, so make sure to check what’s accurate for your setting.

Reports can be made via phone (911 or police nonemergency number) or in person at the police station. The report will often go into a statewide system and perhaps also into a federal system; there are separate systems for children and adults.

There is a general belief that you can’t file a report until the person has been missing for some set period of time, like 24 hours. However, that’s not true. Police will always take a report right away if the person is a child, if he’s an adult of special concern (such as someone with dementia), or if the circumstances suggest the guy hasn’t just gone for a walk. Under federal law, police must immediately take a report in all cases where a person is missing. In California, for example:

There is NO waiting period for reporting a person missing. All California police and sheriffs’ departments must accept any report, including a report by telephone, of a missing person, including runaways, without delay and will give priority to the handling of the report. [source]

When is a person considered missing? Here are the LAPD’s criteria.

Large agencies may have a special missing persons unit. The LAPD unit, for instance, investigates 200-300 cases per month.

If the missing person is a child who has been abducted, authorities may issue an Amber Alert. The criteria for these are fairly narrow. Some states have Silver Alerts for certain missing adults, but this is not as universal as the Amber Alert.

What happens if your character never does show up? Again the rules vary, but he can often be declared legally dead after seven years. The time period will be less if he was known to be in peril at the time of his disappearance—for instance, if he was aboard a plane that crashed into the ocean or present at the scene of a natural disaster. And yet, there are occasions when such people show up later, very much alive, which can create some complicated legal problems. But also some very nice plot twists.