Skip to main content

Boss Murdered Employee and Buried Him Under Septic Tank, But He Was Tripped Up by His Own Lies: Authorities

Booking photo of Daniel Joseph Triplett, missing person image of Brent Mack.

Daniel Joseph Triplett, and Brent Mack.

Alleged paper-thin lies couldn’t stand between an Oklahoma man and a murder case. Daniel Joseph Triplett, 66, has been arrested for murdering an employee and burying the man under a client’s septic tank, authorities said.

The investigation all started with questions from the concerned daughter of victim Brent Mack, 50, said investigators in Logan County, Oklahoma. Mack’s daughter reached out via Facebook to her father’s boss, Triplett, who allegedly told a series of lies that were undermined by documents and surveillance footage, according to an arrest affidavit dated Monday.

In the daughter’s version of events, Triplett told her on Facebook Messenger that he fired Mack on Sept. 20, dropped him off in front of a laundromat, and gave him $1,000 as severance. But he deleted these messages, she said. According to investigators, the daughter provided them screenshots of those messages pre-deletion. She also had access to her father’s phone login information, and investigators said the last call Mack’s phone made was to his Texas-based girlfriend.

That girlfriend told investigators she met Mack online and spoke to him every day for about four months. The last time she spoke to him was on Sept. 20, when he told her he was being picked up to go to work, and later, when he said he was on a job site and did not have good service.

“Okay babe I’ll call you later,” he texted her that day at 12:56 p.m., authorities said. It was the final time he contacted her.

Investigators said they reached Triplett over the phone.

“He stated that he wanted to cut ties with Brent because of his violent demeanor,” authorities wrote. “Dan stated he gave Brent $1,000 as a severance pay. Dan claimed that Brent exited the truck and told him he was going to Texas to get married. Lt. Bruning asked if Brent was upset about being fired and Dan told him he wasn’t upset.”

When asked about where he worked on Sept. 20, Triplett gave an address on W. County Road 69, authorities. The job was for a barn home being built with a fresh septic tank and lateral lines, but the property owner said the septic tank and lateral lines installation was back on Sept. 7.

“[The property owner] stated he had a text message from Dan on September 10, 2021, stating that job had been completed on September 8, 2021,” authorities wrote. “The job taking two days.”

Triplett arrived at the Guthrie Police Department to speak about Mack, authorities said. According to the affidavit, he admitted to being in an area where someone dumped a bag full of Mack’s work clothes, but he was there to check on the lights of a personal truck. He continued to insist he and Mack last worked at the W. County Road 69 address, but several times, he changed his story on where he left Mack, authorities said. Also, his purported story about the laundromat did not hold up, authorities said.

“Dan was shown a copy of the video footage showing him driving by the Holiday Laundry and not stopping,” authorities said. “When confronted with the inconsistencies in the story Dan became very red faced and appeared to be angry. Dan was asked about other jobs and locations and Dan stated he couldn’t remember.”

Authorities with the Oklahoma State Bureau of Investigation and the Guthrie Police Department executed a search warrant at Triplett’s home on Oct. 14. Among other evidence, they discovered a statement book in his truck, showing that he was working on E. County Road 69 on Sept. 20.

The client at that home was getting a septic tank installed. Investigators said surveillance footage showed two people—identified as Mack and Triplett—showing up in Triplett’s vehicle, but only one person was seen leaving. Footage showed Mack entering the septic tank hole and also taking a lunch break in the truck, authorities said.  Video did not show either man fighting each other.

Nonetheless, investigators said they dug up that septic tank and found Mack’s dead body under it.

“On October 22, 2021 Agent Woodward was notified that the Medical Examiners officer had located what’s believed to be a projectile in the chest cavity with an entry wound in the upper left back,” authorities said.

Triplett remains at Logan County Jail without bond as of Wednesday. He faces a count of murder in the first degree, and desecration of a human corpse. His attorney did not immediately respond to a Law&Crime request for comment.

[Images via Guthrie Police Department]

Have a tip we should know? [email protected]

Filed Under:

Follow Law&Crime: