“L.A. Outlaws” (Dutton, 352 pages, $25.95), by T. Jefferson Parker: Suzanne Jones, an eighth-grade Los Angeles high school teacher, thinks she is a descendant of Joaquin Murrieta, a Robin Hood-like bandito who terrorized Anglos during the California Gold Rush. So, she assumes the name Allison Murrieta and goes into the family business.

Flashing an ivory-handled derringer that she calls “Cannonita,” she holds up fast food joints, heists luxury cars and courts fame by leaving behind pink business cards reading: “You’ve been robbed by Allison Murrieta. Have a nice day.”

On his Web site, T. Jefferson Parker confides that he got the idea for this new novel when he poked into the Murrieta legend and discovered no one knows for sure how much of it is true. That got his imagination revving.

“I asked myself ... what if Joaquin had a descendant who was alive today? ... And what if his outlaw spirit still burned in the heart of this modern-day descendant? ... What if she were a beautiful young schoolteacher? What if the opening lines of ‘LA Outlaws’ were: ‘Here’s the deal. I’m a direct descendant of the outlaw Joaquin Murrieta.’ Would you believe her or not?”

Uh. Maybe not.

Over the last decade, Parker has excelled at creating unconventional, yet believable, protagonists for his well-written crime novels. For example, “The Fallen” (2006) introduced Robbie Brownlaw, a homicide detective suffering from synesthesia, a neurological disorder that causes him to “see” people’s voices as colors. “Silent Joe” (2001) featured young Joe Trona, psychologically scared from being raised in an institution.

But this time Parker may have gone too far. Jones-Murrieta is a little too slick, a little too brassy. And her self-destructive behavior is so wildly unlikely that it is difficult to find her credible.

As the novel begins, Allison Murrieta’s crime spree hits a snag when she tries for a big score and overreaches. Fleeing the scene of a diamond heist, she leaves dead bodies in her wake. As the story unfolds, dangerous people are looking for Allison, thinking she has the diamonds. And LA police detective Charlie Hood, who thinks Jones is a witness, wants to talk to her.

Soon, Hood begins to suspect Jones’ double life, but the sap falls for her anyway, compromising his investigation.

The plot unfolds with a lot of unpredictable twists and turns, and as usual, Parker’s writing is tight and vivid. If you can suspend disbelief enough to accept Jones-Murrieta, “L.A. Outlaws” is a fast, exciting read.