Retired Tucson police sergeant Michael Widmer’s first novel is about mass shootings.

It’s called “Intervention,” but what he’s really advocating is prevention.

“Prevention means a couple different things,” said Widmer. “It’s difficult to prevent the person from forming the thought process to decide they are going to do it. Once that commitment is made, that person is not going to turn back. The actual prevention is of the person getting into the school where the children are. And, if he does get onto the school grounds, stopping him from hurting anyone else.”

The novel, published this spring and available on Amazon in paperback and for Kindle, is the story of a specialized law enforcement strike team working out of Tucson that is tasked with anticipating and preventing mass shootings.

Though it is fiction, Widmer, who as a 26-year veteran of the Tucson Police Department supervised violent crimes detectives, included a bonus chapter at the end in which he outlined measures that schools, malls, theaters and other public venues can take to minimize the risk of mass casualties in the event of an attack.

“I’m sick and tired of watching little children hiding under desks and going to school and having to practice duck-and-roll and hide in corners,” he said. “I think it becomes the responsibility of the schools and government to make sure they can’t get into the schools while we argue about what’s to be done about it.

“It’s a relatively simple process to shore up the schools,” Widmer said.

He suggests making each school accessible only through a central entry and exit point. At the entryway would be a locked door that can withstand gunfire, a metal detector and a “greeting window” made of bulletproof glass. Placement of surveillance cameras at the entryway and at other points around a school would pick up anyone approaching the grounds. The cameras would feed into a monitoring station on campus that is continually manned.

“Most of these people — with the exception of a few — walk up with their weapons out and anyone who’s watching (the monitors) can prevent the school from being surprised,” Widmer said.

In the case of new-school construction, Widmer said, campus layout is important. Buildings should be set back from streets and the parking lot to prevent someone from driving up to a classroom or office. That will give whoever is monitoring the cameras time to take note and dial 911.

Playground areas should be walled off and accessible only from within the school and the entire campus should be fenced and lined with surveillance cameras, Widmer said.

In addition, classroom windows should be high and small to protect children from outside gunfire and to keep anyone from climbing in.

He also believes certain faculty or school staffers should be trained to use long-guns that will be secured on campus in case the other security measures are not enough to keep a gunman off campus, Widmer said.

“Let’s make the school safe enough so nobody can get to the kids just long enough for law enforcement to get there,” he said.

In his book, Widmer outlines similar suggestions for malls, theaters and other public venues.

Michael Polakowski, director of The Rombach Institute on Crime, Delinquency and Corrections at the University of Arizona, said Widmer’s ideas for school safety are “interesting in theory,” however, “the problem is … how to economically retrofit the hundreds of schools and malls that already exist.”

Widmer’s ideas would only be practical if they were incorporated into the design plans for new facilities, Polakowski said.

“If you look at the campuses around Tucson you see a variety of systems he talks about, fencing, cameras, access points, etc …. but none of these are impenetrable because they were after-the-fact additions,” Polakowski said in an email.

Adding surveillance cameras would be helpful, although, “cameras are only as good as the money you put in to them — location, number, tracking and warning systems included — and the personnel to observe them,” he said.

Widmer said the financial costs of retrofitting schools with security cameras, metal detectors and security personnel can be offset by cutting back on investigations after shootings and funneling that money directly into school security.

“We spend so much money on things like investigations,” Widmer said. The money spent investigating the 1999 mass shooting at Colorado’s Columbine High School could have funded security at “schools all over the United States.”

Widmer also suggests actions schools can take immediately and at no cost, including changing classroom layouts and the flow of students from one area to another; and preventing visitors, including parents, from coming onto campus without notice and without checking in at a central entry point.

According to online reviews of Widmer’s book, parents have found the novel and accompanying suggestions helpful.

“We need to discuss and resolve the weaknesses of our children’s security at school, and this book is an excellent conversation starter for this specific topic,” wrote the Tucson mother of a high school student.

“After reading this I tested the safety of my own child’s school. I got right in through a side door unnoticed,” wrote another mother.

Added a third reader: “I think the author intended to alert us that this epidemic is not going away and we need to figure a way to fight back and that is just what it did to me.”

Widmer has already written a sequel to “Intervention” and he has started work on a third novel about tracking child predators via the Internet.

“I’m going to pick the things I write about because they are the things I’m passionate about,” he said. “There are two things in this world I hate more than anything: one is a child predator, the other is a mass shooter.”

Contact reporter Kimberly Matas at 573-4191 or Get updates on Twitter: @DailyStarCops