detectives believed sierra bouzigard's killer was an undocumented mexican worker.o clear description of the suspect. monica quaal raced to tell her fellow investigators that this new technology could provide that description. i really think that she's crazy. she was like, "you just have to have faith in me." i was like, "i have faith in you, but this just kind of seems like magic." and she's like, "no, it's gonna work." and so she convinced me and then we convinced the sheriff. narrator: parabon got the unidentified dna sample from sierra's case and put it through a process they call snapshot. snapshot is a way to take that dna and ask it questions. okay, if we don't know exactly who this person is, do we know his ancestry? can we say something about eye color, hair color, skin color, freckling, face shape? can that information at least help the police narrow their investigation and be more efficient? and the answer is yes. narrator: genetically speaking, human beings are remarkably similar. it's only a small portion of the human genome that makes us different from