PORTLAND, Ore. (KOIN) — The bodies of missing mother Karissa Fretwell and her son Billy have been found.

The Yamhill County Sheriff’s Office said the bodies were discovered Saturday in a wooded and remote area approximately 10 miles west of the City of Yamhill. Officials said detectives “led searchers” there. 

Karissa’s cause of death was determined to be a gunshot wound to the head. Billy’s is undetermined, pending tests. The bodies were identified on Sunday by a medical examiner. 

Michael Wolfe, 52, has been indicted by a grand jury for murder and kidnapping in the case. Fretwell, 25, and her 3-year-old son were last seen May 13 and were reported missing May 17.

Wolfe is the biological father of Billy, DNA tests in a child support hearing revealed. Wolfe was arrested at Blue Star Donuts in downtown Portland on May 24. 

Watch: Recap of the Fretwell case so far

In late May, KOIN 6 News obtained the probable cause documents that describe the days after the Fretwells went missing and her relationship with Wolfe. They also describe how police watched surveillance footage of Wolfe on the night of May 13, the night they went missing. 

The documents also show that Wolfe and Fretwell’s cellphones pinged in the same areas that night. Police interviewed Wolfe on May 18 and 20, where he said he hadn’t seen them since April 15. 

Officials said the investigation is ongoing.

 Read: Grand Jury indictment of Michael Wolfe 

Michael Wolfe was indicted by a grand jury for murder and kidnapping in the case of Karissa Fretwell and her son, Billy.