What happened to Merrilee Cox-Lafferty? Details explored ahead of See No Evil on ID

The Dog Knows is an hour-long segment that reenacts the 2018 disappearance and murder of 37-year-old Merrilee Cox-Lafferty, a single mother whose brief trip to Logan, Utah, ended in tragedy. Investigation Discovery will premiere this episode of See No Evil at 9 p.m. ET on Tuesday, June 24, 2025.

Merrilee Cox-Lafferty was abducted, murdered, and secretly buried in a shallow grave in nearby Blacksmith Fork Canyon. An act that led police to charge long-time acquaintance Stacy Robert Willis with capital murder.

By threading together CCTV clips, cellphone pings, and the surprising movements of Merrilee’s loyal dog, detectives transformed a baffling missing-persons report into a homicide case that spanned two states and ended with Willis’s arrest

---

Timeline of Merrilee Cox-Lafferty’s disappearance

Merrilee drove from California to northern Utah with her young daughter on August 17, 2018. She was last seen the next afternoon in Logan and was reported missing three days later. Kin grew anxious when her therapy dog turned up at an area shelter, and her car surfaced 300 miles away in Boise, Idaho.

A month-long search ended on September 14, 2018, when search teams located Merrilee’s body about eight miles into Blacksmith Fork Canyon. Investigators later confirmed she had been buried in a shallow grave at Left Hand Fork, a remote spur of the canyon.

---

CCTV and a loyal dog broke the case

Logan police pieced together footage showing Merrilee’s Australian-shepherd mix in the company of acquaintance Stacy Robert Willis, but no sign of Merrilee Cox-Lafferty herself. The dog’s appearance on video and in social-media posts proved decisive.

As per the Deseret News report dated September 15, 2018, Logan Police Chief Gary Jensen said,

“The dog was pivotal. It offered us some information that we just simply didn’t have and may not have had had we not taken custody of this animal and ultimately release it to people that knew more about Merrilee and her circumstance,”

Detectives also relied on cellphone-tower pings and interviews with children at a Hyrum apartment complex to undermine Willis’s shifting story about a parking-lot argument. Search-warrant affidavits indicate Merrilee Cox-Lafferty’s daughter told police her mother had agreed to deliver marijuana to Willis, a detail that broadened the motive inquiry.

---

Arrest of Stacy Robert Willis and continuing questions

On September 14, 2018, officers arrested Willis, 41, without incident in Hyrum. He was charged in the 1st District Court with capital murder, three counts of obstructing justice, and multiple weapons and drug offenses.

A judge ordered him held without bail. Prosecutors have not yet stated whether they will seek the death penalty. As per the CBS2 Idaho News report dated September 16, 2018, Chief Gary Jensen announced,

“This case has been brought to an end as of yesterday with the knowledge that this is no longer a missing persons case, this is a homicide,”

Authorities noted that Willis had known Merrilee Cox-Lafferty for many years. Cache County Sheriff Chad Jensen told local media the pair were known to each other, and establishing a motive remains an open line of inquiry, per the Desert News report dated September 15, 2018.

The Dog Knows reconstructs Merrilee Cox-Lafferty’s last hours using surveillance clips from parking lots, roadways, and a pet shelter. Interviews with detectives and family members outline how a missing-person case pivoted to homicide, why the dog became a linchpin, and how cross-state cooperation located Merrilee’s vehicle and, ultimately, her burial site.

The broadcast promises fresh insight into the digital breadcrumbs, CCTV, social-media alerts, and phone data that modern investigations now treat as critical evidence. For those following Merrilee Cox-Lafferty’s story since 2018, the episode offers a concise, visual account of the evidence against Stacy Robert Willis and the unanswered questions still shadowing the case.

---

Stay tuned for more updates.

Edited by Bharath S