Detectives Briscoe and Logan investigate a vicious knife attack on two nurses Vicky Hemmings and her roommate Aloma, who survived. Briscoe recalls a similar attack in Brooklyn and learn that that the Brooklyn victim, Mary Davis, and Vicky had worked at the same walk-in clinic. The Brooklyn detective, Lt. Brian Torelli, make an arrest where the suspect David Zifrin confesses to the crime. When Briscoe and Logan interview the suspect, they quickly realize he is mentally challenged and seriously doubt he actually committed the crime. ADA Stone agrees but his Brooklyn counterpart doesn't and Stone soon finds himself appearing as a witness for the defense.
—garykmcd