Michigan investigators looking for a 60-year-old woman missing after her husband shot himself to death during a traffic stop earlier this month received an tip containing specifics of a location in Ogemaw County.

Genesee County Sheriff Chris Swanson said that investigators “found nothing” leading to Kelly McWhirter’s body but asks the writer of the anonymous letter to come forward and talk with detectives, MLive reported.

“You’re not in any trouble,” Swanson said. “You were so specific on your directions that you obviously felt burdened enough to send it. … Maybe you’ve had a bad interaction with law enforcement. Maybe you’re scared. I assure you – you have nothing to be scared about, and the sheriff’s office up there (in Ogemaw) and myself, we will treat you with the respect and dignity.”

As CrimeOnline has reported, investigators began looking for McWhirter On October 16 after she didn’t show up for work. They found a “significant amount of blood” inside her Flushing home, and Swanson said  “there was likely violence inside the home, where Kelly lived with her husband, 57-year-old Steven Higgins.”

Higgins was spotted in Saginaw County and shot himself when a deputy conducted a traffic stop. Back at the couple’s home, detcctives found McWhirter’s vehicle with signs of a struggle inside. They said cell phone records showed that Higgins had driven her car to Ohio and back just days earlier.

Swanson said the letter, which came into the Ogemaw County Sheriff’s Office on October 26, was very specific.

“The tip that said, ‘possible gravel site for Kelly McWhirter,’” Swanson said. “‘Dead end of Melcher Road to north end for Ryan Road to Prescott; west side; fresh dirt; three by six; made by a shovel, perhaps, near this place; wheelbarrow,’ I mean, this is so specific, that they were intentional.”

Swanson said deputies found an “unusual dig site” with disturbed earth at the location.

“There is a spot that even looks so real-life that a person could have been or at least started to have been dug there, but there was no body,” he said.

Swanson said that more than 500 acres of land had been searched as of Wednesday. The search area runs from Ogemaw County to Ohio, in five counties and two states.

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[Featured image: Kelly McWhirter/Genesee County Sheriff’s Office]