Police in San Diego are questioning a Marine over the missing wife of a fellow serviceman. Louis Ray Perez, 45, was already in custody on an unrelated charge of possession of a AR-15 assault rifle stolen from Camp Pendleton, ABC reports. He was the last person seen with Britanny Killgore, 22, who has been missing since Friday. Police, who have been searching canyons north of the city, say Perez has been "very uncooperative" and they suspect foul play, reports the San Diego Union-Tribune. Killgore filed for divorce last week from her husband, a Marine who is serving in Afghanistan. (More Marines stories.)