Author Tess Gerritsen Credit: File photo

Tess Gerritsen was in Italy on vacation when she happened upon the inspiration for her newest book, “I Know a Secret.”

“We were looking at a lot of … paintings and I was getting a little bored of seeing the same thing again and again until I bought a book called ‘How to Read a Painting: Decoding, Understanding and Enjoying the Old Masters,’” Gerritsen said.

The book, by Patrick De Rynck, revealed how master painters would plant clues and symbols in their paintings. After that, Gerritsen said she loved checking out the artwork.

“Whenever I would see a new painting I would look for the symbols, like a treasure hunt,” Gerritsen said. “Then I thought, ‘What if the killer did the same thing: planted symbols that would be clues?’”

Gerritsen was further inspired by something that came up in a conversation with a psychologist about the panic over alleged Satanic ritual abuse cases in the 1980s. The panic, which made international headlines, was everywhere, Gerritsen recalled — including in a case she read about that occurred not far from her childhood home.

“There was a period where everyone was thinking, ‘We have Satantic ritual abuse,’” Gerritsen said. “A lot of [the alleged victims] were impressionable young children questioned in a way that would make them think it was true.”

In “I Know a Secret,” the latest in the Rizzoli and Isles series, Gerritsen masterfully weaves a suspenseful tale about two homicides in different places with victims that have no apparent connection. But as Boston police detective Jane Rizzoli and medical examiner Maura Isles dig into the cases, both of which have unusual circumstances, they discover that there’s much more to the cases than is apparent.

Gerritsen said that the most important element to writing medical dramas with suspense like this is the characters.

“It’s always about having characters that have a very personal or emotional connection to the crime,” Gerritsen said.

Sarah Walker Caron

Sarah Walker Caron is the senior editor, features, for the Bangor Daily News and the editor of Bangor Metro magazine. She’s the author of “Classic Diners of Maine,” and five cookbooks including “Easy...