The squad's hopes are raised when a new prime suspect is tracked down and brought in. The sixth victim, Pat, a crack addict, is found strangled by her own sneaker laces in an abandoned lot only two minutes from the station house. Savarese maps out locations where he might strike next, knowing that the majority of murders have taken place on Thursday mornings. Detectives Valentin and Martinez work with area prostitutes to find customers who might be suspects.
Hopes rise when a prime suspect, with a history of violence against prostitutes, gives a DNA sample.
After an extremely tense wait, detectives learn the sample does not match. Then, in a movie-like turn of events, this suspect gives information that leads to a new prime suspect, Vincent. Vincent is tracked down, brought in but refuses to take a DNA test.