(Portland, OR) -- Arraignment is scheduled today for a man accused in the disappearance of a Salem mother and her three-year-old son. Police arrested 52-year-old Michael Wolfe at a Blue Star Donuts store in Portland Friday on two counts of aggravated murder and two counts of first degree kidnapping. Police say he's the biological father of three-year-old Billy Fretwell, who was last seen May 13th along with his 25-year-old mother, Karissa Fretwell. Police are still searching for the two but say they have probable cause to charge Wolfe with murder. KATU reports Fretwell and Wolfe were engaged in a custody battle for Billy.