The Case of Mandy Rose Reynolds

Mandy Rose Reynolds, 26, was murdered in April 2023 after her cousin Derek Daigneault came to live with her in San Marcos, Texas. Her burned remains were discovered in a plastic storage container in Robinson, where her dog Titan remained at the scene. Daigneault was convicted of murder and sentenced to life in prison.

Mandy Rose Reynolds was originally from Idaho and had moved to San Marcos, Texas, where she was considering starting college. Her cousin, Derek Daigneault, came to Texas from Kansas and stayed with Mandy in her apartment. In the days before her death, Mandy had expressed fear of Daigneault to her father and had considered sending him back to Kansas following an argument. She was the only other person living in the apartment with Daigneault and her dog, Titan. On April 5, 2023, Robinson police responded to a report of a brush fire near a residential development. Investigators discovered that what appeared to be a fire was actually a burning body inside a large plastic storage container. The victim could not initially be identified.

Mandy's body had been placed inside a large plastic storage container and burned in a developing residential area near Heston Circle in Robinson. A white Labradoodle was found near the burning remains, barking and refusing to leave the area. After the body was removed, the dog remained at the location the following day. Animal control officers eventually recovered him and discovered through his microchip that his name was Titan and that he belonged to Mandy Reynolds. Investigators recovered a .380 shell casing and other items from the burned remains, including an urn containing the ashes of Mandy's grandmother that she normally carried in her purse.

Titan's microchip gave investigators their first major lead. Robinson police contacted San Marcos police, who went to Mandy's apartment and found it completely empty. Her belongings had been removed and her black Honda Accord was missing. Surveillance footage from a San Marcos Walmart showed Daigneault purchasing a large plastic storage container, a shovel and a gas can on April 4, the day before Mandy's body was discovered. The footage also showed him leaving in Mandy's car with Titan visible inside. The container was later determined to match the type found at the crime scene. Police tracked Mandy's Honda Accord to Wichita, Kansas. On April 8, Wichita officers attempted to stop the vehicle. Daigneault fled, leading police on a high-speed pursuit before crashing the car and fleeing on foot. He was later found hiding inside a grocery store. Mandy's .380 handgun was recovered from the vehicle. Ballistic evidence later linked the handgun to the shell casing found at the scene and to the fatal gunshot. Daigneault also contacted Robinson police using Mandy's phone and attempted to impersonate her after her death. The call further connected him to Mandy and the investigation.

Derek Joseph Daigneault was convicted of murdering Mandy Rose Reynolds following a four-day trial in McLennan County, Texas, in November 2024. On November 7, 2024, he was sentenced to life imprisonment, with parole eligibility after a minimum of 30 years. Daigneault appealed his conviction, but the Texas Tenth Court of Appeals affirmed the judgment on April 9, 2026.

The investigation became notable for the role played by Titan, whose presence at the scene enabled police to identify Mandy after her body had been burned beyond recognition. Prosecutors later credited Titan and the cooperation between law-enforcement agencies in Texas and Kansas as key elements in bringing the case to a successful conclusion.