A tension runs through “The Anniversary” by Amy Gutman, and not just because the novel is a whodunit – or more precisely, a “who’s doin’ it?” The tension is between reality and hope, between reality and denial.

While the title refers to a specific event in the book, the title resonates more broadly because anniversaries can be marked by remembrance, regret and hope. They can make us think of what was, what is, what may come, and what might have been if only… . All of these ideas vibrate throughout the thriller, which was partly inspired by a forensic science conference in Waterville and part of which is set on a Maine island.

“The Anniversary” (Little Brown & Company, 2003) is about three women connected to an executed sexual serial killer. Five years after he was put to death, each of the women receives a simple, unsigned note reminding her of the anniversary. One of the women is the killer’s ex-girlfriend, who turned state’s witness at his trial; another is the reporter turned true-crime writer whose first book, a smash hit, was about the killer; and the third is the lawyer who unsuccessfully argued his appeal. Shortly thereafter, one of the three women is murdered in a style that mimics the executed killer’s. So, who is the copycat killer apparently avenging the executed murderer?

Along with the central theme of denial-versus-reality, “The Anniversary” is about “the effect of violence on those left behind,” Gutman said in a telephone interview from her home in Northampton, Mass.

Her interest in this kind of “fallout” led her to read Ann Rule’s “The Stranger Beside Me,” about serial killer Ted Bundy, and “The Phantom Prince,” the out-of-print memoir of Bundy’s girlfriend. In 1989, Bundy was executed after being found guilty of murder. He eventually confessed to killing 28 women, almost all college age, from 1974 to 1978. While the girlfriend eventually told police about Bundy’s suspicious behavior, Gutman said that the memoir is “one of the archetypal stories of denial.”

“I found the memoir really fascinating,” Gutman said. “How would you feel if you found someone you loved was killing people?”

In “The Anniversary,” Gutman slices elements out of Bundy’s and the girlfriend’s lives and folds them into her story.

In her novel, Gutman said, the murderer’s ex-girlfriend turned a blind eye to her suspicions, hoping they would not be true, hoping their relationship would work out. “That core issue for her is universal, one that I had experienced, ” Gutman said. “There’s something in her we all identify with.”

In the novel, Gutman writes that the ex-girlfriend saw “an endless series of bright red flags she’d done her best to ignore.”

In contrast to her characters’ efforts at ignoring or denying reality, there is a stark effort to describe in stinging clarity the manner in which the women are murdered, the police procedures used in tracking the killer, and the methods used in trying to understand the murderer’s thinking.

It is in these stretches that Gutman reveals her years spent as a reporter in Tennessee and Mississippi and later as a lawyer in New York. In fact, not to be morbid, in broad strokes Gutman dismembers her own careers and spreads them among the characters in the book, for examples, the reporter-turned-writer and the lawyer. “I know those worlds so it makes sense that I use them,” she said.

She began the forensic-medicine research for what became “The Anniversary” while in Maine. After her first book – “Equivocal Death” – was published in 2001, Gutman said she wanted to escape to a place to develop her ideas for a second novel. She landed on North Haven, a “very evocative setting,” that she turned into fictional Blue Peek Island, one of the three major settings, along with New York City and a thinly disguised Northampton, of “The Anniversary.”

While on North Haven, she began talking to medical examiners as part of her research. One referred her to a forensic science conference held in Waterville. The New England Seminar on Forensic Sciences, which is held annually at Colby College, attracts state medical examiners and law enforcement officers from across the country. “These are very smart, very interesting people but with an unusual take on the world,” Gutman said.

Two years ago at the seminar, she saw a slide of a murdered woman whose arms had been slit down the back from her upper arms to her wrists, cuts that had been made after she was dead. “It wasn’t particularly gruesome for these kinds of cases, but it was striking in the way she was displayed,” Gutman said.

“How can people be like this? What’s going on in their brains? How can they be this way?” she wondered.

The slide, along with the memoir by Bundy’s girlfriend, became “the key seeds from which the book grew,” Gutman said. “The image preceded the characters and the plot.”

While trying to delve into the minds and actions of such killers, there is safety in doing it through fiction she said: “Looking at it in the context of a story … you control the ending and things work out, order is restored,” she said. “That’s part of the appeal of this genre.”