PLEASANT PLAINS TOWNSHIP -- Human remains found buried in the backyard of a Pleasant Plains Township residence have been identified as a man who went missing in 2017.

Lake County Sheriff Rich Martin said that personnel with the Michigan State Police Crime Lab identified the remains as Richard Allen Ashbrook.

He noted a cause of death has yet to be determined.

Martin said the case is now being investigated as a homicide, but police believe it was an isolated incident.

"We're going to handle it as a homicide until we find anything otherwise," he said. "It is our belief it is contained to a personal issue. There is no threat to the area or the public at large, nor has there ever been at any time."

Ashbrook's remains were discovered buried in the yard behind a home in Pleasant Plains Township on June 6.

Martin said the home was the last known residence of Ashbrook, where he had been living with a woman who police believe Ashbrook, at some point, was in a relationship with.

Det./Lt. Brad Nixon, with the Lake County Sheriff's Office, said Ashbrook, who was from the Baldwin area, was reported missing by his family on Feb. 11, 2018, and was last seen in November 2017.

Martin said at the time the report was filed, police performed a well-being check of Ashbrook's last known residence.

"We sent someone out to the residence to make contact with his last known whereabouts and spoke with the individual there. They said they hadn't seen him and he left and had moved out and didn't know where he was," Martin said.

Martin explained due to Ashbrook's distant relationship with his family members, police did not believe any foul play or criminal activity was involved.

"This family member was one the rest of the family didn't have rigorous contact with, but it had been way too long to be with no contact," Martin said. "It was determined at the time that it may not be anything more than someone who had left."

However, Martin said members of Ashbrook's family reached out to the sheriff's office about a year ago, asking that police begin actively looking into the case again.

"When the family contacted me later, I thought there was more to the story and we needed to look at it as someone who was actually missing, not just somebody who doesn't want to be found," Martin said.

Martin added although the missing person case for Ashbrook had never been closed, it wasn't being actively investigated until the family reached back out, since police had determined it was likely Ashbrook had left the area.

Nixon said through investigation of a credible tip, police were able to obtain a search warrant for the Pleasant Plains Township property, which led to the discovery of Ashbrook's remains.

Martin declined to comment on the identity of the person who provided police with the tip, as the case is still under investigation.

At the time he went missing, Ashbrook was 47 years old.