Police: Trenton man dies of heart attack after strangling, burying girlfriend in the backyard

May 10—New details have been released about an Edgefield County death investigation involving a Trenton man and his girlfriend.

Joseph Anthony McKinnon, 60, and his girlfriend, Patricia Ruth Dent, 65, were found dead in their backyard on Saturday.

On Saturday morning, the Edgefield County Sheriff's Office, Edgefield County Coroner's Office and Edgefield County EMS responded to a house in the 100 block Tanglewood Drive in Trenton after receiving reports of an unresponsive man lying in his yard.

McKinnon had no signs of trauma and natural causes were suspected. However, while investigating the death and making notifications to the next of kin, a second body was located in a freshly dug pit, according to a release from the sheriff's office.

"Evidence gathered at the scene, along with statements from witnesses aided investigators to build a timeline, leading us to believe that Mr. McKinnon attacked Ms. Dent while inside their home," according to the release. "Mr. McKinnon then bound her and wrapped her in trash bags before putting her in the previously dug pit."

A witness told police that McKinnon had dug the hole prior to the day of the suspected murder, according to an incident report obtained from the sheriff's office.

Police said McKinnon partially filled the pit before having a cardiac event and dying.

On Monday, autopsies were performed on both bodies and the cause of death for McKinnon was confirmed to be a cardiac event.

Dent was found to have died by strangulation.

McKinnon does not have any prior criminal history, according to a South Carolina Law Enforcement Division (SLED) background check.