The bodies of Karissa Fretwell and her 3-year-old son, missing from Salem since May 13, have been recovered from a remote area west of the town of Yamhill, law enforcement officials announced Sunday afternoon.

Fretwell was shot to death but the cause of death of her son, Billy Fretwell, hasn’t been determined, authorities said.

Michael J. Wolfe, 52, of Gaston, has been in jail since May 25 on charges of aggravated murder and kidnapping. Court records show that he is the father of Billy Fretwell.

The bodies were found Saturday about 10 miles west of Yamhill. The town is about nine miles south on Oregon Highway 47 from where Wolfe lives. Police had earlier focused their search in remote areas around Hopewell, including searching several ponds. Authorities didn't disclose what led them to that area, and the statement Sunday provided no details on how the new search site was identified.

Police “searched the heavily wooded and very remote area for about two hours before locating two bodies,” according to a joint news release from the Yamhill County Sheriff’s Office, the Salem Police Department and the Yamhill County District Attorney’s Office.

The search was conducted by members of the Yamhill County Search and Rescue, Washington County Search and Rescue, North Oregon Search and Rescue, Mountain Wave Search and Rescue, McMinnville Fire Department, the Yamhill County Sheriff's Office, Oregon State Police and the Yamhill City Police Department.

A police affidavit supporting Wolfe’s arrest last month said a Fretwell relative, not identified in the affidavit, arrived at Fretwell's apartment in west Salem on May 17. It had been four days since the relative heard from Fretwell, according to the affidavit. The family member said it was "very concerning," because she regularly checked in.

The relative found the door to Fretwell’s home unlocked, the television on, with several necessities left behind. Those included her bank card, her Oregon Trail card for benefits and eyeglasses "she can't be without."

They were "items Karissa would need to take care of William," the affidavit said, and her two cars remained parked outside.

By then, Fretwell had missed three shifts at work, the affidavit said. Salem detectives who talked to other friends and family who reported that she had not been seen since May 13.

One of the last people to see her that day was her babysitter, who told detectives Fretwell picked up her son about 4 p.m. that day.

“The babysitter stated over the past three months she has had several conversations with Karissa about William’s father (Michael) and Michael’s wife. The babysitter said Karissa told her they had threatened Karissa that they were going to take William and get custody of him,” according to the affidavit.

This story will be updated.