Huntington Beach-based Colleen Fitzpatrick is a noted forensic genealogist: That means she uses DNA analysis combined with sources such as family records and photographs to help identify unknown people. She’s worked on such high-profile cases as the “Unknown Child of the Titanic,” Amelia Earhart, and the “Arm in the Snow” case, which involved identifying remains from a 1948 plane crash in Alaska. Fitzpatrick tells us about the field and where it’s heading.