Oregon father arrested, charged with murder in disappearance of 3-year-old, child's mom: Police Karissa Fretwell and her 3-year-old son have been missing since May 13.

Police in Oregon have arrested a 52-year-old man and charged him with murder after he was named a person of interest in the disappearance of his 3-year-old son and the child's mother.

Karissa Fretwell, 25, and her son William Fretwell, who goes by Billy, were last seen on May 13, and relatives reported them missing on May 17, the Salem Police Department said.

Michael John Wolfe was arrested at 2 p.m. at a donut shop in Portland and has been charged with aggravated murder and kidnapping, police said. Authorities have still not found Karissa Fretwell or Billy.

"Although we have charged Mr. Wolfe with aggravated murder, that does not mean that William and Karissa are dead,” Salem police Lt. Treven Upkes said at a press conference Friday.

Police would not discuss a motive and said additional charges may be filed against Wolfe based on further investigation.

Wolfe was identified by police as a person of interest on Thursday. He is listed as the father of William Fretwell in a child support document filed in Polk County, Oregon, in 2018, according to a clerk at Marion County, Oregon, court. A Salem police spokesman would not confirm Wolfe's connection to Fretwell to ABC News, or say what led police to say he was a person of interest.

Karissa Fretwell has sole custody of the 3-year-old, according to the Yamhill County Sheriff's Office.

"Information gathered during the investigation" has led police to a property in rural Yamhill County, the Yamhill County Sheriff's Office said Thursday.

"Law enforcement officers are searching this property in hopes of locating Karissa and William, or discovering evidence which may lead to their location," the sheriff's office said. Investigators did not elaborate on what led them to this property.

Wolfe lives in Gaston, Oregon, while Fretwell and Billy live in West Salem, officials said.

Karissa Fretwell is 5 feet 9 inches tall and weighs about 135 pounds, according to police. She has blue eyes and naturally blond hair, but she dyes it red.

Billy has blond hair and blue eyes. He is about 3 feet tall and weighs about 30 pounds.

Anyone with information was asked to call the Salem Police Department at 503-588-8477.

ABC News' Mark Osborne contributed to this report.