JACKSONVILLE, Fla. -- Jeff Mackey, 58, pleaded not guilty to second degree murder Monday.
Police say Mackey admitted to killing his ex-wife, Kimberly Mackey, in May. Her body was found buried more than 1,000 miles away in Missouri.
The pair had been divorced for 15 years but recently started living together when the murder happened, according to investigators.
After the shooting, investigators said Mackey wrapped her body in a blanket and buried it in Missouri before returning to the First Coast.
Initially, Mackey was reported missing from her mobile home in the 2700 block of Suni Pines Boulevard on Memorial Day weekend.
Mackey was eventually arrested at a St. Augustine hotel.
Authorities said an argument over relationships between the couple triggered the murder.
Prosecutors said in the future, Mackey could face additional charges in relation to the murder.
Mackey's pre-trial hearing is scheduled for August 14 at 9 a.m.