An 18-year-old girl is found raped and strangled in a harlem stairwell. Dna is collected from the victim’s body and is compared to that of other rape suspects being held in jail; it doesn’t match. Another girl with a similar description is found dead, and police feel they have a serial killer on their hands. A man’s name is found from the phone records of one of the victims, and authorities would have to attempt to obtain dna sample from the man to prove his guilt.