Part of a folklorist's job is listening to people tell the most incredible stories.

Balancing the fascination of fieldwork, however, is routine filing and library research. And then there's the comparing of notes with other folklorists. Which is how I came to know folklorist Eleanor Wachs, who studies violent crime the way I do choking Doberman pinschers and Mexican pets.For the past decade or so, while I've been collecting urban fictions told as fact, Wachs has gathered the sometimes embellished but presumably true stories told about crime victims in New York City.

I group my urban legends in broad categories such as "Automobiles," "Animals" and "Crime" and give them titles like "The Hook," "Alligators in the Sewers," and "The Attempted Abduction."

Wachs' system of filing data is simpler: She arranges the stories she hears as M's, R's or MRs - Muggings, Rapes or Murders.

The stories, told to her over the years by New York residents, usually take the form of: "Did I tell you about the time my neighbor was mugged?"

Reading her book, "Crime Victim Stories: New York's Urban Folklore" (Indiana University Press, 1988), I noted that some of the story categories, such as "The Fated Victimization," "The Trickster Offended" and "The Clever Victim," sounded like legends.

All the accounts Wachs presents were first told as literally true, she writes. But Wachs discovered that "threads of legend plots . . . form the kernel of some of these crime-victim stories."

When New Yorkers tell about muggings, for example, they sometimes include details borrowed from the urban legend I call "The Middle-Class Mugger."

In this legend a man beats up and takes a wallet from a stranger who had bumped him on the street, believing that the stranger picked his pocket. When he returns home, though, he discovers that he had left his wallet on the dresser that morning.

Another of Wachs' New York crime-victim narratives tells about a man on a bus. Out of the sleeve of his trenchcoat drops a woman's hand with valuable rings still intact on the bloodied fingers.

The tellers of this horror story are never first-person witnesses of the event. They seem to be retelling a version of the legend I call "The Severed Fingers" as if it happened to a friend of a friend.

One of the most dramatic stories Wachs collected described an elderly blind woman, alone at home, whose door was forced open as far as the door-chain would allow by a would-be burglar.

According to the story, the intruder grasped the woman's hand and scratched her arm with sandpaper, attempting to force her to undo the chain.

But the woman, taking strength from her fear and outrage, clenched her fist and broke all the man's fingers - "like spaghetti." He ran away and later was captured at an emergency room where he sought treatment.

Wachs points out discrepancies in the story, aside from its lack of a first-person source. Sandpaper seems an unlikely assault weapon; a chained door must be closed before it can be unlatched; and an elderly woman would probably lack the strength to break anyone's fingers by force alone.

These details showed Wachs that her informant was probably borrowing from a version of the well-known urban legend "The Robber Who Was Hurt."

This legend usually describes an attempted entry by a man who sticks his hands or fingers into a half-opened door, window or mail slot. A woman inside injures the intruder with a knife, a hot poker or an electric iron.

The hurt robber is recognized when he shows up back home or at a hospital seeking treatment for his hands.

In Wachs' version of this story - as in many legends - a supposedly true account is enhanced with a marvelous detail lifted from a piece of folklore.

(C) 1989 United Feature Syndicate Inc.