When Swedish crime novelist Camilla Lackberg was 16, she came across an old photograph album of her father’s. It was shocking.

There were pictures of Jens Lackberg as a young man with a wife and infant child. She knew he had a prior marriage — she had two much-older stepsisters — but this was a mystery. This was another family altogether.

Her mom privately told her the story: Some 30 years earlier, Jens and his first wife, Annie, and their toddler, Kurt, were in terrible car collision. Annie was killed instantly. Kurt died the next day. Jens staggered on to a new life.

He died three years after she learned of his tragedy; she’d never worked up the nerve to ask about it.

“You never really know them,” she says of family and the labyrinth of secrets held within relationships. “It had to have such a huge effect on him, his life. And we never even mentioned it.”

She says this during a long lunch at a downtown Washington restaurant, on a quick U.S. tour for “The Stonecutter,” her third book to hit American shores, coming out May 9.

It’s her first visit to the District, and she and her publishers hope that “The Stonecutter” will prove to be her U.S. breakout.

Somber family history aside, she’s outgoing and funny, brown hair spilling over her shoulders, leaning forward over the table as she talks.

“If I can hit No. 1 on the New York Times bestseller list, I’m thinking of having the entire list tattooed on my body somewhere,” she says, giggling, a trace of that Scandinavian accent. “It would be fabulous.

It would also be predictable. Since Lackberg burst onto the Swedish scene with 2003’s “The Ice Princess,” her nine novels have sold millions of copies and have been published in more than 35 countries. She was the best-selling female author in Europe in 2010. She has sold more books in Sweden than Stieg Larsson.

She debuted stateside in 2010, and her first two thrillers, “Princess” and “The Preacher,” have approached combined sales of 100,000 in hardcover, paperbacks and e-books. That’s good, but neither of the books made an appearance on any major bestseller list.

Jessica Case, the senior editor at Pegasus Books who signed Lackberg just as the Larsson phenomenon was beginning, thinks the first two books have built an audience that will grow.

“They’re sort of the definition of a locked-room mystery,” says Case. “You meet the criminal somewhere. No one’s coming in and out of this little Scandinavian town. They’re not overly political or overly graphic. They’re not your standard bloody fare.”

“Stonecutter,” like the first two books, is set inFjallbacka (fyeel-BACH-ah), a tiny resort town on Sweden’s southwestern coast where Lackberg was raised. Also like the others, there’s a present-day murder with twisted roots in an unsolved older crime, and detectives must unravel one to solve the other. The back-story, as the series develops, is the relationship of village native Erica Falck and detective Patrik Hedstrom as they move from romance to parenthood.

Here’s how she starts the new one, describing a fisherman’s macabre catch:

“He didn’t lose his composure until the pale, lifeless body fell to the deck with a thud. It was a child: he’d pulled a child up from the sea. A girl, with her long red hair plastered round her face, and lips just as blue as her eyes, which now stared unseeing up at the sky.”

Lackberg, 37 and a former economist, takes her books seriously but without pretense: “I’m not lying awake the night before they announce the Nobel Prize in literature.” (Sweden’s official Web site offers a similar prosaic description of her attitude: “Läckberg has nurtured a public image of herself as a successful business woman with crime fiction as her product.”)

And despite the dark family secret and her trade in murder, she gives every appearance of leading the kind of happily-ever-after existence usually limited to fairy tales.

She was picked by readers of a Swedish newspaper as “Woman of the Year” in March. She’s a celebrity contestant on the nation’s version of “Dancing With the Stars.” She is married to Martin Melin, a police sergeant in Stockholm, who became a national sex symbol after winning “Expedition Robinson,” the Swedish “Survivor,” in 1997.

They have five children from their blended families (two each from prior relationships, one child together). His blog, “Coola Pappor” (“Cool Dads”), is such a hit that it led to a book with the same title last fall.

“I talked to her a lot what to write about, but I did all the writing myself,” he says, laughing, in a telephone interview.

Between crime novels, Lackberg paired with a childhood friend to write a cookbook, “The Taste of Fjallbacka,” which was so popular that it led to a second. She wrote a children’s book about her and Melin’s child, “Super Charlie,” which became a game on an iPhone app.

He tattooed her name on his rib cage and rides a Harley. She has been known to pose in a bikini.

They stopped by a nudist beach in France on vacation on a lark, but they fled when it dawned on them that they might be photographed.

“I mean, the clerk at the grocery store was naked!” she says. “The guy selling ice cream on the beach was naked!”

Real life, she says, is actually a little less glamorous.

Their children are 2, 4, 7, 8 and 9. The four children from prior relationships rotate in and out of the house on shared custody schedules. She takes the kids to school, then tries to start writing by 9 a.m.

Sometimes that works. Mostly, she says, her mind tends to wander to the temptations of checking the Internet and her e-mail.

“One of the things I’m really good at,” she says, “is procrastinating.”

The writing day ends at 4 p.m., when the day-care shuffle begins: Pick one kid up here, another there, soccer practice, dinner, homework, baths, teeth-brushing, bedtime.

The family ties and the international jaunts of book promotion have cut her book production from one per year to two in five years, as per her latest Swedish contract.

It’s fine with her, she says. Life is good. No need to try to be something she’s not.

“I don’t feel the need to prove myself by writing the next generational novel,” she says, sitting back in her restaurant booth. “I’m just so happy doing what I’m doing.”