The Special Victims Unit takes a doctor (Lorenzo Scott) who has been accused of molesting little boys to trial. Brian Cassidy testifies but, when the doctor's lawyer (Daryl Edwards) suspects Cassidy of being racist, Cassidy loses it, which results in a mistrial. However, when Cassidy turns up to Benson's apartment with blood on him and Dr. West is found dead, Benson must decide if Cassidy is guilty of murder or if Cassidy is innocent as he claims, complicating Rollins' and Benson's relationship. Stone and Benson's relationship gets off to a rocky start, all while a determined Homicide detective (Kylie Bunbury) investigates Cassidy for murder especially when her sister tells her that she likes the new da and later afther the case star meets with peter again in a bar but this time he see her and gets feelings for her and went to her and introduce himself Peter stone and she introduce herself as well tells him that she is Olivia Benson younger fraternal twin sister and she reminds him that met before out the court house a while back ago Peter laugh and told her he know they didn't know each other names she just bumped into him she blush giggles and said sorry about that she just had to say goodbye to barba before left he told her he understands and said it's okay and they talk for a while and get to know each other