 A raped victim identifies her attacker from a line-up, after correctly giving the investigators his license plate number and physical description. DNAs recovered, however, indicate that the suspect is not guilty, as only 7 out of the 13 alleles matched, which suggest that the rapist is a relative. The suspect s brothers are all tested for their DNAs and none are a positive match. The resolution of this investigation is a shock to everyone due to the rarity of a genetic condition.