Gotham season 01 episode 06:

10 years ago, Randall claimed to be possessed by the sheep god and committed many bloody cases. Harvey witnessed his partner Edith kill Randall. Now there are girls killed in Gotham, just like the sheep god. Harvey wants to know where the killer learned Randall's top secret killing method. Another girl was kidnapped in Gotham. Harvey and Gordon successfully caught the murderer and rescued the girl. Harvey discovered another truth in the murder case. It turned out that the therapist hypnotized the patient and created the murder. Montoya found a witness who witnessed Gordon killing the penguin character. After she arrested Gordon, the penguin character suddenly appeared.