The opening of J.A. Jance’s new suspense novel, “Exit Wounds,” is a killer.

Loner Carol Mossman and her 17 dogs are found dead in her mobile home. Small-town Arizona Sheriff Joanna Brady is called to the scene. She soon discovers that solving Mossman’s murder is like peeling the layers of an onion to expose its rotten core.

It’s a sizzling summer in Cochise County. The heat is what killed Mossman’s dogs — they were trapped inside the trailer. With their mistress dead — killed when bullets ripped through the thin aluminum shell of her locked door — the dogs slowly succumbed as the temperature in the mobile home continued to soar.

But who killed Mossman?

It turns out that two women, who were recently found shot to death and stripped naked in a remote area in New Mexico, were killed by the same gun. And here’s the twist: the bullets are 86 years old.

While considering the possibility of a serial killer, Brady learns about Mossman’s eccentric relatives, which leads her to the family’s terrible incestuous secret.

Sheriff Brady has a full plate — including a re-election campaign and a newly discovered pregnancy — and Jance does an excellent job illustrating the difficulties of balancing a demanding job and family responsibilities.

The author also builds her story around a real-life contemporary social concern: people who suffer from the psychological disorder known as hoarding. Hoarders have an endless availability of unwanted dogs and cats. They believe they’re helping, but the animals are usually undernourished, unvaccinated and neglected, Jance explains in an author’s note.

She also makes a plea for readers to consider a pet rescue operation when choosing a new family pet.