According to author Mary Kubica, the central crime in It’s Not Her was inspired by one of America’s most infamous unsolved cases: the 1981 Keddie Cabin Murders (“A True Crime Addict: A Guest Post by Mary Kubica.” B&N Reads, 9 Feb. 2026). In April of that year, three people—Glenna “Sue” Sharp; her teenage son, John; and his friend, Dana Wingate—were found brutally murdered in Cabin 28 of the Keddie Resort, an isolated vacation spot in Northern California’s Sierra Nevada mountains. The bodies were discovered by one of Sharp’s children, 14-year-old Sheila, who had spent the night with a friend at a neighboring cabin. Two more of Sharp’s children—five-year-old Greg and nine-year-old Rickey—were sleeping in a back bedroom with one of their friends, Justin Smartt Eason. These three children were left alive. Sue’s 12    -year-old daughter, Tina, was missing from the scene; her remains were discovered three years later.

Mistakes were made during the course of the initial investigation, and some have even accused law enforcement of covering up for powerful suspects. The case remains unsolved, although modern forensic techniques have led to recent breakthroughs. Plumas County Sheriff’s special investigator Mike Gamberg’s testing of evidence preserved at the time of the crime has matched DNA with one of the early suspects in the case. Gamberg believes, however, that the crime was committed by multiple suspects (Metcalf, Victoria. “Keddie Murders Revisited Part 1: New Evidence Discovered Links Living Suspect to Grisly Scene.” Plumas News, 13 Apr. 2018).

Kubica’s novel mirrors these terrifying circumstances by staging a brutal double homicide within a remote rental cottage during a family vacation. In another similarity to the Keddie murders, one child disappears, one is home but spared by the killer, and another comes home from a sleepover to discover the bodies at the crime scene. This real-world precedent grounds the novel’s fictional horror in a disturbing reality, reminding readers that vacation settings can become sites of unimaginable violence. The unsolved nature of the Keddie murders adds another layer of dread, underscoring the vulnerability of those in isolated locations and the terrifying possibility that such crimes may go unpunished.