Suspense novelist Lisa Gardner researched her new book, “Live to Tell” at the Cambridge Health Alliance’s Child Assessment Unit and appears to have based a character in it on the unit’s Kathy Regan.

For a New Hampshire writer, Lisa Gardner spends a lot of time around Boston. For her latest novel, “Live to Tell,” she spent a lot of time in Cambridge — specifically at the Cambridge Health Alliance Child Assessment Unit, which served as Gardner’s model for a pediatric psychiatry unit in a plot that involves child murderers.

Gardner’s time in Cambridge isn’t over. At 7 p.m. July 14 she’ll be at Porter Square Books for a book signing co-sponsored by the alliance. While the event is free, a portion of sales of “Live to Tell” will be donated to its Alliance Foundation for Community Health, which supports the Child Assessment Unit.

Gardner visited the unit nearly a year ago and met with staff including nurse manager Kathy Regan to conduct research for the suspense novel, said David Cecere, media relations manager for the alliance.

“Regan has received national acclaim for establishing a standard for psychiatric inpatient care by adopting a more humane, trauma-sensitive treatment model for patients. Earlier this year, she got the 2009 Award for Innovation from the American Psychiatric Nurses Association,” Cecere said.

Gardner found her experience at the unit and with Regan uplifting and has expressed her gratitude in “Live to Tell,” which is being published by Bantam Books this month, acknowledging her time at a “first-class operation,” Cecere said.

The word “uplifting” is a hopeful sign for readers of the novel, which otherwise sounds dark: It begin with the murder of four members of a family and what appears to be a suicide attempt by the murderer — the father and husband.

In this fourth outing of D.D. Warren, Gardner’s fictional Boston detective, the murder interrupts a blind date and introduces Warren to a devoted mother, Victoria Oliver who, the official description goes, “has a hard time remembering what normalcy is like. But she will do anything to ensure that her troubled son has some semblance of a childhood. She will love him no matter what. Nurture him. Keep him safe. Protect him. Even when the threat comes from within her own house.”

And there’s another character that may sound a bit familiar:

Danielle Burton is a survivor, a dedicated nurse whose passion is to help children at a locked-down pediatric psych ward. But she remains haunted by a family tragedy that shattered her life nearly 25 years ago. The dark anniversary is approaching, and when D.D. Warren and her partner show up at the facility, Danielle immediately realizes: It has started again.

Booklist called the book a “gripping thriller” that “ends with a resolution that is creatively and emotionally appropriate.”

Porter Square Books is at 25 White St. in Cambridge. For information, click here. The alliance provides care in Cambridge, Somerville and Boston’s Metro North communities. It includes three hospital campuses, a network of primary care and specialty practices, the Cambridge Public Health Department and the Network Health plan. It is a Harvard Medical School teaching affiliate and affiliated with the Harvard School of Public Health, Harvard School of Dental Medicine and Tufts University School of Medicine.

This post includes material from press releases.