14 Things You Need to Know to Understand Cop Shows

by Jennifer Li Shotz
Originally Published: 

If this scene feels familiar—and if you didn’t have to Google a single word in the first paragraph—then you’ve got a bad case of petechial hemorrhagitis, that 9 p.m. craving for a hit of one-hour television police procedural, where the cases are hot, the investigating officers are hotter, and complex forensic processes take four to six minutes to resolve—but they’re always resolved.

That neat and nifty resolution is catnip after a long day of juggling work, family, your needy cubicle mate, mortgage woes—all the scruffy stuff that real life is actually made of. The cheap thrill of being a Castle or CSI or Closer fan is feeling like you’re in the squad room, across the desk from your favorite TV gumshoe. And what better way to belong than to talk the talk? Here’s our binge-watching primer on the most useful police procedural terms:

1. Petechial hemorrhaging

The phrase that started it all. Technically, petechiae are weensy red or purple spots visible on the surface of the skin and caused by burst capillaries just under the skin. In forensic medicine, petechiae can be an indicator of strangulation. In TV forensics, petechial hemorrhaging is the autopsy clue that, amazingly, singlehandedly breaks the case and sets the wheels of justice in motion. It’s the phrase that’s meant to sound complex and scientific but actually kind of just means “broken blood vessels in the eyeballs.” It’s also the snippet of dialogue that’s equivalent to a hot bath, a glass of Prosecco and a pint of dairy-free ice cream to me. Instant relaxation.

2. LUDs

LUDs, or Local Usage Details, are magical, like tiny little electronic leprechauns who sprinkle clues like breadcrumbs. Some detectives say it like a word; others spell it out, L-U-Ds. Either way, they’re the phone records of a suspect, which always lead to 1) a burner phone, 2) an affair, or 3) an illegitimate child/second family/illicit career. Oh, and technically they require a warrant, so, you know…cops can’t actually access them instantly.

3. Vic/Perp

The victim and the perpetrator. The vic was leading a double life (i.e., accountant/violent ecoterrorist) and the perp is the second person interviewed in connection with the case, or the first guest star face you recognize.

© Getty/Spencer Platt

4. “Have uniforms canvass the block.”

“Canvassing the block” is when patrolmen and women knock on doors and ask a loopy old lady, a Hispanic male in a white tank top, or a prim rich white person if they saw or heard anything at the time of the crime. Nine times out of 10, they will have seen nothing, unless the prim rich white person says something racist, in which case it is actually relevant.

5. “Run it through the system.” (“We got a hit.”)

The system varies—it may be AFIS or CODIS or facial rec or ballistics—but it will turn up a match (usually to the former cell mate of a suspect). And fast. In real life, the process can take hours or days—and requires significant human interaction with the database. Not so in the precinct of pretend.

6. “Put out a BOLO”

Formerly known as the APB, or All-Points Bulletin, the BOLO goes out over the radio and tells other officers what the perp (or missing child) looks like. Sounds official, but it’s really just an acronym for Be on the Lookout. Disappointing, right? I was hoping for something more colorful, like “Bad Operator Loose, Okay?” or “Beastly Opprobrious Lecherous Offender.”

7. Rigor/time of death

Second only to petechiae, rigor (short for rigor mortis) is key to establishing time of death, which establishes a timeline for the crime, which is vital to ruling out the husband, until he’s ruled back in by 1) the discovery that a text message allegedly from the deceased was actually sent by the husband in a crafty bit of post-mortem digital trickery, 2) the revelation that the “happy” marriage was actually a sham, because she was an emasculating shrew and he an ego-challenged sociopath, or 3) hidden money troubles.


Gunshot residue and gunshot wound. The first is on the perp’s hands, the second is how most real people are murdered. But not on TV, because neighbors actually hear such things and that would make for too many open-and-shut cases. Even for television. Nope. On TV, being killed isn’t awful enough, so victims are strangled, strung up, knifed, gutted, flayed and splayed for all to see.

9. A partial

A partial fingerprint. Meaning, the suspect was dumb enough to touch something. Luckily they were also dumb enough to have committed a previous crime, for which they’re “in the system.” They will not, however, be guilty of this particular crime—they will have had a drink/sex/a fight with the victim, but s/he was alive when the suspect left. This last fact will be verified by an alibi, such as conveniently timed drinking in a bar or cheating on a spouse.

10. The Feds/Local PD

© Getty/Rob Lord

Both are pronounced with evident disdain, as if the words burn on the tongue. This is the Yankees v. Red Sox of the genre. Depending on whether your preferred show is fed-based or PD-based, your position on this will vary. It basically means the opposing team is encroaching, and btw, they’re either a bunch of earpiece-wearing meatheads or rule-breaking mavericks with cop-father or murdered-mother issues. And they suck.

11. Unsub

This stands for “unknown subject.” Because “perp” wasn’t good enough. Popularized by the particularly bloody show Criminal Minds. Also the name of a late-’80s David Soul vehicle, which aired for only eight episodes. Fun fact: Soul, famous for his star turn as Hutch in Starsky & Hutch, also played the title role in Jerry Springer—The Opera onstage in London.

12. Tox screen

Forensic toxicology screening. Also known as the reason detectives get called down to the autopsy room, where the ME will print out a piece of paper and read the results while standing over the very dead body they are discussing. Some things you would never know if you trusted what you see on TV: Blood samples are taken from more than one part of the body—the femoral vein, the heart—because chemical concentrations vary. Tissue samples can come from the liver, brain, kidneys and vitreous humor—also known as the jelly in your eyeball chamber. Yes. YOU HAVE AN EYEBALL CHAMBER (well, ideally two) and IT HAS JELLY IN IT. Oh, also, they check stomach contents and bile. Yum. Anyhoo, tox screens are a series of tests that take as long as six weeks to process—so when those results come in, that body will be long buried, not on the slab.

13. Blood spatter

Have you ever seen actual crime scene photos? I’m not suggesting that you seek them out if that’s not something you’re into. They’re seriously upsetting. But I will say this: They’re not pristine. They’re not neat and tidy, because people’s lives and houses aren’t neat and tidy. In real life, there’s crap everywhere—even dead people once had trouble keeping up with the junk mail. So, the idea that there are these perfectly visible patterns writ large in human blood, just waiting for criminal investigators to shine a flashlight on them (why is the power never on at crime scenes, btw?), is plain silly.

© flickr/retrocactus

I have no doubt that blood spatter and other clues like it are extremely helpful in solving crimes. If and when they can be spotted among the packages that need to get shipped back to J.Crew and the bag of old toys that didn’t make it to Goodwill before that whole homicide thing happened.

14. “Stop. Right there. Can you get in closer?”

“Yeah, I can enhance it.” Click, tap, tap, click.

“There. That’s him. We got him.”

The biggest load of baloney any TV writer could ever conjure up. Ever. I am married to someone who makes his living working with film and video. Let me tell you, this common police procedural exchange—which invariably cracks the case—has led to many outbursts on our couch. I mean, full-on swearing and throwing of balled-up socks at the TV. This. Doesn’t. Happen. At least not the way they say it does. Grainy video, my friends, is grainy video, no matter how many nerdy-but-handsome techs in cute lab coats tell you otherwise.

This list only scratches the surface, but it’s enough to get you started. Now sit down, grab the remote and let the magic of syndication wash over you. And don’t worry if you can’t remember all this vocab—on TV, the bad guy always gets caught. (Unless he doesn’t, in which case he becomes a recurring guest star who taunts and torments the lead character in a creepy game of cat and mouse, eventually kidnapping the lead, until the lead’s partner busts down the door and saves the day.)

Photo: Getty/Scott Olson

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