With certain recurring stories it's difficult to know whether life is imitating legend, history is repeating itself or both.

A case in point is the tale involving something undesirable that is unwittingly stolen, like a dead cat in a package, a grandmother's corpse on a car roof-rack or a urine specimen in a minibottle.These three mishaps of thievery are subjects of well-known urban legends, yet similar things do occur in real life.

That's why several readers sent me clippings of a recent news story about the theft of a package containing . . . well, let me quote the original report.

The following item appeared in the Seattle Post-Intelligencer on Aug. 9. It's what journalists call a "bright," a humorous tidbit used to balance serious news:

"Crime happens.

"It happened about 1 p.m. yesterday at the intersection of Rainier Avenue South and South Henderson Street.

"As a driver waited in his car, a young man ran up, reached into the car through an open window and stole a small box. The startled driver, however, didn't want it back, and police didn't investigate - they felt the perpetrator got what he deserved.

" `The package contained dog-doo that this good citizen had picked up,' a police dispatcher reported.

"Quipped police spokesman Mark Amundson: `The city's pooper-scooper law seems to be working.' "

The details convince me that it's factual. Still, the story parallels a legend known for at least 20 years. Usually the dog droppings are being carried in an old purse or a shopping bag by someone such as an eccentric aunt or an elderly neighbor who is out walking a dog.

These word-of-mouth unverified friend-of-a-friend (FOAF) accounts come true when someone actually has a stool specimen or a bag containing dog droppings snatched away.

A 1988 news story names a woman from Florida whose purse, which contained the cremated remains of her dog, was snatched. True or not, this event resembles a couple of old legends.

Who wouldn't repeat such a funny story, and who - in repeating it - might not unconsciously change details?

But back to the Seattle story. You noted, I'm sure, the everyday informal terms "dog-doo" and "pooper-scooper," as well as the sly allusion to a less-polite saying in the two-word lead sentence. The story already sounds like oral tradition.

As journalists elsewhere repeated the story, they also modified it.

It has happened before: A 1978 clipping from San Francisco reported a dog-doo snatching, referring to a civic official involved as the "Poopervisor."

When United Press International circulated the Seattle story, they paraphrased the police dispatcher, retained the quotation from Amundson and had the motorist "sitting in traffic" instead of merely waiting. Street names were dropped.

The Associated Press version shifted the story's perspective by beginning "A thief got the straight poop." The AP dropped the Amundson quotation, kept the dispatcher's words and had the motorist "waiting at a stoplight."

Some local columnists rewrote the story. For example, Jon Hilkevitch in his Aug. 10 "Newsmakers" feature in the Chicago Tribune began, "OK, it was a common street crime, but the circumstances should not be pooh-poohed."

Headline writers, whatever version they had to work with, often included the words doo, pooh, poop or pooper.

After a couple of days the Seattle dog-doo theft story disappeared from the press, though it may surface again in the tabloids where weird news is often expanded and recycled.

I suspect, too, that the story will be remembered more-or-less accurately by countless people who hear or tell the legends about nasty things being stolen. In the future, these legends may elicit responses like, "Oh, but that really happened," or "I read about that in the paper."

So it won't be getting any easier to distinguish legends from life.

1990 United Feature Syndicate Inc.