For a former reporter turned novelist, it all starts with a tip. Someone has done something to someone. Read all about it.

“Often I’m lifting ideas from the newspaper,” says Jan Brogan.

Brogan, a reporter for 20 years, about half of them with The Providence Journal, now lives in Westwood, Mass. Recently she published her fourth book of fiction, Teaser (St. Martin’s Press, 304 pages, $25.95), the latest in a series featuring the character Hallie Ahern.

The first book in the series was set in Boston, the last three in Providence. The genre is mystery with a crime component.

“There is always some sort of industry of crime. I’m much more interested in that kind of crime than a husband killing his wife. I’m not sure if crimes of passion scare me or that I just don’t like them. When crimes are done for money, that makes more sense to me.”

In her previous books, Brogan has researched and written about such topics as gambling and insurance fraud. This time it’s about online predation of teenagers.

“I usually start with some sort of social ill. I start with an issue I want to explore.”

And that starts with the news. For Brogan, reality prompts reverie, and a book.

Teaser is based on news out of North Smithfield in 2006. Three teenagers — one 19, the other two 16 — posted nude and sexually suggestive photos of themselves on the social networking site called MySpace. And as a result, they were prosecuted for distributing child pornography.

“That sounds pretty harsh. But you learn that there’s a whole community online trading pictures. If you post a picture of yourself, you’re contributing to the bank of photographs that are traded by pedophiles.”

This got Brogan to thinking: “Why did they have to be prosecuted? What would happen if they didn’t stop them? What’s the worst thing that could happen?”

That worst-case-scenario, which includes death and disappearance, is the basis for Brogan’s book. It also includes accurate information, according to Brogan, who learned about the online social networking world by joining it, creating personal accounts on MySpace and Facebook, and by enlisting the consultation services of an expert, a teenager: Emily Homonoff, a senior at East Greenwich High School.

“I’m an adult. I don’t live my life online. I wanted to see what it means to teenagers and how exactly they use it.”

The social networking sites allow users to create personal accounts where they can post comments and pictures for others to see.

“It’s like a meeting place, like a bar is to an adult. Facebook is not as scary as MySpace. You have to approve who gets into your page. You ‘friend’ people.”

There are also numerous chat sites, some specific to topics or regions.

“I was in what was supposed to be a Rhode Island chat room, but there were people there from Australia. I don’t know why. But they were talking about sex.”

That’s a primary subject of conversation in chat rooms and networking sites, according to Brogan. Parents should know that, especially if they have teenagers who are 13 or 14 and are impressionable and vulnerable.

“Pedophiles give each other tips on how to do this. They know what they’re doing. Parents are fools if they allow their children to have a laptop computer in their room with the door closed.”

Brogan’s book may be about a racy and sensational subject, but she says her treatment of it isn’t.

“It’s not at all graphic. I didn’t want to be producing more of this exploitation by writing titillating scenes in my book.”

Being an author, Brogan says, has long meant also being a promoter. Over the years, she has given lots of readings and talks at book stores and libraries. But now, she says, the nature of book promotion has changed.

Tune in to see. Check www.youtube.com/

watch?v=qEw5Tswct2E. This brings you to a movie-like trailer for Teaser.

“It’s not the norm. But it’s becoming more common.”

Last month The New York Times reported a rapid rise in the number of books promoted by Web sites and videos. The article cites the AuthorBytes organization that started in 2003 and now has more than 200 clients, and the Circle of Seven Productions, which last year produced 140 promotional book videos.

“I wanted to try a video. I have a good friend who has a video production company and he likes my work and offered his services for free.”

Otherwise, Brogan says, her video, which she wrote and co-directed and features teenagers who volunteered their time, would have cost $12,000 to $15,000.

Brogan says she asked the teenage girls to come to the shooting with their mothers.

“The video starts off provocative with two girls in bikinis on a beach. I didn’t want the mothers to think I was a child pornographer.”

As with the previous books in the Hallie Ahern Mystery series, Teaser involves the same three subjects as the others: mystery, love and the declining newspaper industry.

“My books are reality based. I need to keep current with what’s going on. The books reflect the era in which they’re written.”

Jan Brogan will be at Books on the Square, 471 Angell St., Providence, at 7 tonight to read from her book Teaser.

brourke@projo.com