Before a sentencing hearing this past June, prosecutors tried numerous times to get the 68- year-old to cooperate in connection with the Hendershot case.
He refused, until Tuesday, where he revealed a burial site to investigators.
Michael believes Petry's time behind bars, the start of a 15-year sentence, convinced him to change his mind.
"At his age and physical health, it's gonna be tantamount to a end of life decision," he says.
Michael says the overriding reason for the deal was to give Hendershot's family a sense of closure.
So does the discovery of the remains mean that Petry buried them?
"He had the means, he has a backhoe on the property," Michael says. "There was disturbed earth, she's clearly buried. He would have the means and the opportunity."
In September, Petry's 15-year firearms sentence is to be reimposed.
He'll also faces charges of forgery and obstructing an investigation.
Prosecutors say Petry is also to plead guilty to using Hendershot's money inappropriately, possibly after she passed away.
"For this person, its more or less he's looking at a life sentence and he's getting 90 days off on the front end," Michael explains.
Authorities still have to get toxicology reports and DNA samples to make a positive ID on the remains.
Michael says if evidence of a homicide are uncovered, he may--- or may not, prosecute the charge.
"A lot of answers we'll never have in this case," he says. "But the one we do have, is where this person, these remains came from. And if they turn out to be Laurie Hendershot, which is likely, we'll solve at least that mystery."
