GREENUP COUNTY, Ky. — A Kitts Hill man involved in a polyamorous relationship charged with the 2013 murder of his co-worker admitted the crime Wednesday in Greenup County Circuit Court.

Arthur Quigley, 32, also pleaded guilty to tampering with evidence.

Quigley was arrested and charged with the murder of Mary Dixon, 40, of South Shore, whose body was found behind Hobby Lobby in Russell on June 29.

Dixon was reported missing by a nephew on June 27 after she didn’t return to her mother’s home after a shift at Subway restaurant in Russell. Her vehicle was still in the parking lot with her purse still inside.

According to an autopsy report, the main cause of death was blood loss from a cut to Dixon’s throat. She also received blunt force trauma to the head.

According to police reports, Quigley, Dixon and another woman, all employees at Subway, were involved in a three-way relationship.

During an interview, Quigley told the detective he informed Dixon the relationship was “getting to be too much for him to handle” and that it was “killing him and tearing him apart.”

Quigley also said he had recently found some text messages between Dixon and the other woman about their sexual relationship and allegedly told Dixon that he wanted to end the three-way relationship.

According to the report, Quigley said Dixon responded by saying she wanted the other woman more than he did, at which point Quigley said he “lost it.”

During the interview, Quigley admitted to cutting Dixon’s throat with a box cutter that was thrown off the Ironton-Russell Bridge.

Quigley will be sentenced on Feb. 2.