Jerri Williams works as the director of media relations for SEPTA. She’s the person you see on TV or quoted in the newspaper when SEPTA makes a big announcement or is defending itself. But before that Williams spent 26 years with the FBI investigating economic crimes, sometimes as an undercover agent.

And earlier today Williams announced she would be making an even bolder career transformation: She plans to retire from her job at the end of the month to become a full-time crime fiction writer. She’s already finished her first novel and is shopping it around with a literary agent to publishing houses.

Williams has always been a voracious reader. She says she reads two books a month (most recently M.L. Stedman’s The Light Between Oceans). For crime fiction, Dennis Lehane is her favorite author. Her favorite book, though, is Tom Wolfe’s Bonfire of the Vanities.

As much as Williams loves reading crime fiction, she has a problem with the genre. Williams says most books cast the FBI agents as investigating serial killers, when it’s rare for the FBI to do that.

“There are so many other things we do, especially with corruption,” she said. “I always wanted to see if I could make an interesting story on corruption, fraud and greed.”

That’s what she plans to do with her work. In her career, Williams investigated enough noteworthy cases to provide some ideas. Once, Williams worked as both an undercover agent and investigating agent in a telemarketing scheme where a company was over-billing other companies for goods it sold by bribing employees at those other companies with Sears gift certificates. To catch the schemers, Williams and a partner started their own fake company so they could be offered the bribes.

She wants to give her books a mark of authenticity while not getting too bogged down in those details.

“(Author Joseph Wambaugh) said most good crime novels are not about the crime but how they affect the investigator,” she said.

Williams started her first novel, “Pay to Play,” in 2007 when she was still working with the FBI. She wrote mainly on weekends and finished it in 2012. The novel is about “a female FBI agent investigating corruption in the Philadelphia strip club industry (who) is blackmailed by a one night stand she picks up in one of the clubs. How far will she go to stop him from destroying her career…and her marriage?”

SEPTA is also part of this first novel, at least in the background. Williams says at one point some characters even ride the El. During her years of work with SEPTA, she would also write down interesting comments she heard and use them as a basis for dialogue.

But she won’t draw too much from either her work with the FBI or with SEPTA:

“It’s not a newspaper article. It’s a story,” Williams said. “It’s got to be entertaining.”

Mark Dent is a reporter/curator at BillyPenn. He previously worked for the Pittsburgh Post-Gazette, where he covered the Jerry Sandusky scandal, Penn State football and the Penn State administration. His...