The Murder of Brent Mack

The investigation moved quickly once Brent's daughter Raychelle provided investigators with the screenshot evidence of Triplett's Facebook Messenger messages and Brent's cell phone records. Triplett had deleted the messages on his end but had not anticipated that Raychelle had already saved them. Those screenshots placed Triplett as the last known person to have contact with Brent.

The critical break came from two sources: surveillance footage and Triplett's own business records. Security cameras at the Holiday Laundry and the Guthrie Public Library directly contradicted Triplett's claim that he had dropped Brent off there, showing his vehicle passing without stopping and with no passenger. When investigators executed a search warrant on Triplett's home and vehicle, they found his job logbook. The last recorded job on September 20 was not in Crescent, as Triplett had told them, but at a residence on West County Road 69 in Mulhall, where a septic tank had been installed that day and the homeowner had been paid.

The Mulhall homeowner cooperated fully and turned over their home security footage. That footage documented the entire workday — both men arriving, digging, taking lunch, and returning to work. After lunch, Brent descends into the excavation hole. He is never seen leaving. The footage then shows Triplett operating the backhoe to lower the concrete tank, backfilling the hole, and driving away alone.

On October 21, 2021, a joint operation by the Guthrie Police Department, the Oklahoma State Bureau of Investigation, and the Oklahoma Medical Examiner's Office excavated the site. State anthropologists used a probe to locate Brent's body several feet below the tank. His wallet and ID were in his pants pocket. The medical examiner determined he had been shot in the upper left back, with a projectile recovered from the chest cavity. No motive was ever publicly confirmed. Triplett claimed self-defense at trial, asserting Brent had pulled a gun on him inside the hole. Prosecutors and the evidence contradicted this account entirely.