During my days as a prosecutor in the Manhattan district attorney's office, I had the privilege of working with a brilliant young forensic pathologist in the city's office of the chief medical examiner. Now, Dr. Jonathan Hayes is joining me on the literary side of the law, with the publication of his first novel, Precious Blood, which introduces New York City forensic pathologist Edward Jenner.

What was your inspiration for Precious Blood, and what led you to put aside the scalpel and pick up a pen?

I'd been writing professionally about food and travel for several years before I felt ready to write a novel. Precious Blood has its origins in my heavily Catholic childhood—I was educated, in part, at a monastery school in southwest England. I actually started the book in Oaxaca in Mexico, after a day spent visiting the city's Gothic churches. Their walls and ceilings have insanely detailed gilt decoration, thousands of hours of painstaking work; I was struck by the fact that religion and obsession are often very closely linked. It wasn't a big step from there to the book's essential plot.

I thought Precious Blood would be a procedural, based on your experience as a medical examiner. I'd characterize it instead as a thriller, and wonder if you make that distinction as well? Is it an accurate portrayal of forensic pathology?

Much of the traditional appeal of the procedural has been getting a glimpse behind the scenes of a murder investigation. The thing is, in 2007, you can't turn on a TV without seeing a forensic show; everyone now has a pretty clear sense of what cops and forensic scientists do. Precious Blood does have some procedural insights, but they're subtle details, rather than the core of the book. I think of it as a hybrid: the forensic thriller.

You and your colleagues did heroic work in the aftermath of 9/11, which I witnessed firsthand, and for which I have the most profound admiration and gratitude. How did that experience help to shape your fictional creation?

After 9/11, I found it really hard to work on Precious Blood. I realized that I couldn't go forward without admitting what had happened to the city and to me, so I rewrote the book from the beginning. The recovery effort was an intensely painful thing; I couldn't have got through it without the people I worked with. In the book, some of the cops are named after the amazing guys on my recovery team.

Will there be more Jenner books?

There's a direct sequel to Precious Blood, then I'm sending Jenner on a pretty brutal three-book arc.