art cred: Lydia nichols

Five or six years ago, I wound up selling books on an Argosy ship. The cruise line was trying to attract different clientele in the off-season and someone in marketing had the grand idea of serving fancy dinners as popular authors gave lectures—and the inaugural author for this books 'n' boats campaign was Ann Rule.

You've probably heard of Rule. She's written 26 true-crime books—basically inventing the genre—and she's one of America's best-selling authors, right up there with Stephen King and Anne Rice. But there's nothing about Rule that screams "best-selling author." She's a heavyset older woman with a cheery demeanor and a saint-like patience for stupid audience questions.

I also think that she single-handedly ruined the Argosy's dinner-with-an-author program. I still recall the disgusted faces in the audience: People who'd paid a lot of money for this experience were pushing away their untouched froufrou dinners because Rule was up at the podium happily discussing exit wounds and bruises caused by nylon-rope strangulation, while billboard-size photos of same were projected over her head.

I especially remember the look on her face as she was talking about men who kill their wives and the mothers of their children. She wasn't ebullient, exactly, but it was the kind of look that someone gets when she's doing something that she dearly loves: Her expression was full of a weird kind of grace.

Decades ago, Rule was a Seattle cop, but she was a young mom with five kids and she found that solving crimes didn't pay as well as writing about them. She started out covering murders and rapes for lurid magazines with names like Master Detective and Front Page Detective. While working on her first book, about a still-at-large Northwest serial killer, Rule was volunteering at a crisis line with a man named Ted Bundy. Rule and Bundy became friends. And when Bundy was later revealed as the same killer that Rule was researching, her book about the case, The Stranger Beside Me, became a publishing sensation.

It was the kind of bizarre coincidence that can only happen once in a career. And most authors, after a scoop like that, would destroy themselves trying to replicate the success of the first book—but Rule has been relentless in both her publishing schedule and in her study of crime. Rule attends the same conferences and seminars that detectives do, on matters like CSI and search and seizure, and in recent years her knowledge has surpassed that of most experts: She's the headliner at a lot of conferences now, too. This woman who looks like anybody's mother, and who regularly blogs about Paris Hilton, Anne Heche ("She dumped Ellen without looking back, and, I think, hurt her badly"), and Chuck Woolery ("One of the handsomest game-show hosts over the years"), is a certified instructor on topics such as Sadistic Sociopaths and Serial Murder.

Rule isn't a writer of beautiful prose; her books are full of clunky sentences. The newest, Too Late to Say Goodbye, begins with a choice example: "With every book I write—and this is number 27—I realize more just how many lives are affected when one cruel and conscienceless person decides to take another human being's life." Frequently, parts of her books veer into prose as purple and maudlin as their titles: A Fever in the Heart, The End of the Dream, A Rose for Her Grave.

But the unimpeachable fact of Rule's writing is that it's excellent journalism, and endlessly compassionate. She interviews subjects exhaustively; she attends all court proceedings related to a case; she delves into the family and personal histories of both the victims and their killers. She keeps in contact with all her subjects and frequently updates her books and website with fresh information. Once you get past the (admittedly, often rough) first two chapters of any Rule book, it becomes a compulsion: You're involved in the crime, as swept into the events as is humanly possible. If that's not some kind of good writing, I'll gladly stick with the bad.

The thing about seeing Rule in person is that it's hard not to be charmed by her: She's a woman with both a grandmother's taste in ugly dresses and a nerdy, encyclopedic understanding of forensics. When the question comes up, as it always does, about why she does what she does, the answer is so corny, but delivered so earnestly, that you can't doubt her. She always patiently explains, that weird grace in her smile again, that if she can save just one woman from a rage-filled creep of a husband who tries to bounce her off the floor like a Super Ball, or convince one promising young coed to not take that beer with the slightly funny aftertaste at the questionable party, then she feels like she's done good work. You have to believe her, when she says it, and it's a hell of a lot more than Stephen King could say for himself when he gets asked the same question.

Ann Rule reads on Thurs June 28 at Third Place Books, 7 pm, free.