JACKSONVILLE, Fla. -

The 58-year-old ex-husband of a woman Jacksonville police have been looking for since Memorial Day was arrested Monday and charged with murder.

Kimberly Dawn Mackey, 48, was last seen May 26 in the 2700 block of Suni Pines Boulevard in Jacksonville.  Police had said they suspected foul play.

"We learned that a neighbor saw the suspect loading what appeared to be a blanket, which had a body, or what was believed to be a body, wrapped into it... into his car," said Assistant Chief Chris Butler.

Police said they actually had missing-persons reports filed for both Kimberly Mackey and her former husband, Jeffrey Mackey.  Police found him in Missouri and detectives flew there to interview him. 

Mackey initially told officers he last saw his ex-wife leaving the mobile home Monday on a motorcycle with an unknown man.

Detectives returned to Jacksonville to continue to investigate and soon learned Mackey was also back in Florida and staying at a St. Augustine motel.  When they asked him to come in for a second interview, Mackey changed his story to say he'd killed Kimberly after they had an argument, and he buried the body in Missouri.

"We believe she was murdered here in the trailer. He then placed her in the car and transported her up to Missouri, where he dumped the body," Butler said.

Investigators say they found the body of the mother of two in a gully (pictured, courtesy of KCTV) in Excelsior Springs, Missouri.

Police said they believe she was shot, but the cause of death will be determined by an autopsy.

The only comment investigators had regarding motive was that it was over "relationship issues."

Butler said the couple had been divorced for several years and had two adult children, who live out of state.

Kimberly Mackey’s brother, Jesse Rodriguez (pictured), said Monday that his gut told him Jeffrey Mackey was responsible. But neighbors said they are shocked, telling Channel 4 that there was never any sign of trouble.

"It's a mystery to me," said William Burger, who lives 25 yards from where investigators say Jeffrey Mackey killed his ex-wife. "I don't know how these things happen right in the family like this. It's a terrible situation."

Rodriguez said the thought of his sister being thrown out like trash in a Missouri field is almost too much to bear.

“It makes me feel disgusted,” Rodriguez said. “How can someone do something so cruel to somebody so sweet and innocent?

“She was a loving and caring mother. Not only a loving and caring mother but a loving and caring sister.”

According to a police report, Jeffrey Mackey withdrew large amounts of money from his bank accounts before leaving Missouri, and he left behind all of his clothing and personal items, including his cellphone, computer and two dogs.

Rodriguez said the couple's two sons, John (pictured with Kimberly) and Adam, who are both in their mid 20s, are now left to make sense of this tragedy, and are leaning on their faith, which they hope will eventually lead them to forgiveness.

“I don’t wish any bad punishment on him. God’s going to serve him his,” Rodriguez said. “God forgives and so can I.

“I have a lot of mixed feelings going through my heart and my mind right now. Some of it’s just anger and some of it… I feel pity for him.”

Jeffrey Mackey is expected to make his first court appearance Tuesday morning. A funeral service is still being planned in Michigan, where Kimberly Mackey was from.