CARTERSVILLE, Ga. -- The Georgia Bureau of Investigation has finished its autopsy on Heather McDonald, the missing mother whose body was found in the woods this week.

Hunters found McDonald's body in the woods in Haralson County on Sunday. She was located some 40 miles from her house.

More tests are pending before authorities can determine the cause of McDonald's death.

Meanwhile, a person of interest in this case, Richard Harden, has spent more than two weeks in the Bartow County jail on unrelated charges.

Harden, a convicted child sex offender, wasn't registered with the state.

"Yeah, I knew that he had gotten in trouble. In the '80s he spent a lot of time in jail," said Stefan McDonald, Heather's husband.

That may be all the McDonalds knew about Harden's past. But it's not the whole story.

Richard Dale Harden was first charged with child molestation in Bartow County in 1984. He was arrested again in 1988 for enticing a child. He was locked up for two decades.

After he got out of the Johnson State Prison in 2010 he soon met Heather McDonald's parents.

"We met him at church," said Lisa Chatman, Heather's mother, "but we haven't seen him in a few years."

But Heather has seen him.

One of Harden's neighbors tells 11Alive's Ryan Kruger she saw Heather at his apartment multiple times.

"I wouldn't say I knew him well," Stefan McDonald said. "He didn't seem like a dangerous person. He didn't seem to have that side in him."

Stefan McDonald does admit to giving Harden's name to police.

"I think he might know somebody that knows something. Or he might run in the circles of people that might know something about Heather," Stefan McDonald said.

Photos | Missing Cartersville mother Heather McDonald

U.S. Marshals were called in to track down Harden originally because he failed to register as a sex offender. Also, not the first time he's been arrested for that charge since 2010.

But Marshals are telling 11Alive they were told Harden is a person of interest in this case.

They found him in Carroll County on Hay's Mill Road. According to the GBI, Harden put a gun to his head and pointed a gun at the marshals. They opened fire.

"That's just not him," Lisa Chatman said, "that's not who I would know."

Law enforcement sources tell 11Alive they are waiting until a final cause of death is determined before moving forward.

Harden is being held on violation of the Sex Offender Registry on no bond.