(CNN) Today is National Donut Day. Or Doughnut, if you're a stickler for spellings.

Indeed, like a Dalmatian to a firefighter, doughnuts have been so closely associated with cops that it's become a trope.

Your office Someone is bound to bring in some

Dunkin Donuts but you have to buy a drink

Movies propagate it -- from "Police Academy" to "Wreck-It Ralph."

The public peddles it -- such as, when demonstrators dangled doughnuts in front of officers during an Occupy Wall Street rally.

And sometimes police themselves perpetuate it, such as the Chicago cop who allegedly accepted a $5,000 bribe -- stuffed in a doughnut bag.

But behind every stereotype, there's usually an ounce of truth. So we set out to seek how this one came about.

The love goes way back

"It's not an urban legend," says Michael Krondl. He would know; he literally wrote the book on this topic, namely "The Donut: History, Recipes and Lore."

Doughnut or donut: The delicious debate Between mouthfuls of sugary bites, we can't seem to agree on the correct way to spell the darned thing. The dictionary spelling is, of course, doughnut. Fried sweetened dough in the shape of a ring. Makes sense. But sometime in the late 20th century, we started to shorten it -- thanks to Dunkin' Donuts. Its stores became ubiquitous. And 'donut' started creeping into our vernacular -- kind of like our creeping waistline.

The cops-doughnut love affair was in full bloom even before the 1950s.

At the time, cops working the graveyard shift didn't have much choice when they wanted to take a break.

There were the all-night diners. But the food took too long.

And then there were the doughnut shops. They opened early to get ready for the morning crowd. And a cop could walk in, get a coffee (staying awake is important in fighting crime) and a doughnut to wash off the aftertaste.

But there was one more draw, Krondl says.

"A lot of times, young women were working behind the counter."

Turning punchlines into headlines

Which brings us to today. Officers have more choices. And also, they're way more health conscious.

So, understandably, some are bothered by the stereotype. We asked police down in Atlanta about it, but a spokesman politely declined to comment.

Others have embraced it.

In Illinois, officers climb rooftops at Dunkin' Donuts every year to raise money for Special Olympics.

Thanks to all who donated to @SpecialOlympics by participating in #CopOnARooftop event. Schaumburg raised $5,530! pic.twitter.com/dFD7HIlaeb — Villageof Schaumburg (@SchaumburgIL) May 23, 2016

In Portland, Oregon, when weed became legal, police issued a tongue-in-cheek visual aid to show how much is legally acceptable to carry. They shaped the weed into doughnuts.

And in Michigan, when a local doughnut shop was on the verge of closing, officers pooled their money and bought it. They called it -- what else -- Cops and Doughnuts . Today, you can buy a "Don't Glaze me, Bro" T-shirt there and munch on a "Misdemeanor Wiener."

So if you run into an officer today, don't be afraid to share the Doughnut Day love and offer them a warm, sugary glazed one. Especially if they're writing you a ticket.