Can POA file charges on someone stealing a title and car?

My uncle's ex gf allegedly stole his title and car after he had an debilitating illness. The title was in his home where she lived at the time. She has now taken off with his car and registered it in her name. She claims that he signed the title to her and a personal check while he was in the hospital. Her only witness was her parent. He claims that he never signed anything to her and since the very beginning he was always asking me where is car was. So, that does lead me to believe him. Just there were days where he could have been coerced in the beginning. What could a POA do in this situation?