You don't have to be a private investigator to find missing loved ones. Several methods law enforcement and private investigators learn and use to track down folks or missing folks can be learned without a law enforcement degree. You cannot arrest or confront folks but you can use the web and public documents to search for folks as well as observations. Once you find them you can notify authorities. They are basically the same methods as "real" (not TV) bounty hunters use. Good Luck.