The disappearance and murder of Merrilee Cox-Lafferty, a 37-year-old California mother, shocked the nation in August 2018. Merrilee had embarked on a vacation to Utah with her minor daughter and her service animal, Coco. Her trip was meant to visit an old acquaintance, Stacy Robert Willis. However, this seemingly innocent visit took a dark turn that ultimately led to her tragic demise.
The investigation into Merrilee’s disappearance utilized digital data, surveillance footage, and witness statements to piece together her final movements. A crucial breakthrough came when her service dog, Coco, was found wandering alone, prompting authorities to intensify their search efforts. Tragically, Merrilee’s body was eventually discovered in a secluded area of Blacksmith Fork Canyon, leading to the arrest and indictment of Stacy Robert Willis for her murder.
The case of Merrilee Cox-Lafferty garnered national attention and was featured in an episode titled “The Dog Knows” on Investigation Discovery’s series “See No Evil.” The episode aired on June 24, 2025, at 9 p.m. ET on the Investigation Discovery (ID) channel and was subsequently made available for streaming on Max and Discovery+ platforms.
A fact-based timeline of events surrounding Merrilee’s murder sheds light on the tragic sequence of events that unfolded in August 2018. Merrilee’s journey from California to Cache County, Utah, on August 17, marked the beginning of a chain of events that would ultimately lead to her untimely death. On August 18, Merrilee was last seen alive in Logan, Utah, visiting Willis to exchange drugs for cash. Witnesses and surveillance footage corroborated her presence at Willis’ home, but she was never seen leaving.
Subsequent developments, including the discovery of Merrilee’s abandoned vehicle in Boise, Idaho, and the revelation of Coco’s whereabouts, played a pivotal role in cracking the case. Merrilee’s body was eventually found buried in a shallow grave in Left Hand Fork Canyon, leading to Willis’ arrest on charges of aggravated murder and other offenses.
The legal proceedings following Willis’ arrest shed light on the motive behind Merrilee’s murder, citing a mix of drug-related disputes and personal conflicts. Willis remains held without bail in Cache County Jail, awaiting further court proceedings. The case of Merrilee Cox-Lafferty serves as a sobering reminder of the dangers that can lurk beneath seemingly ordinary interactions.
In June 2025, Investigation Discovery revisited the case in an episode of “See No Evil,” highlighting the role of digital forensics in unraveling the mystery surrounding Merrilee’s tragic fate. The episode served as a poignant reminder of the importance of vigilance and awareness in ensuring justice for victims of heinous crimes.
