Righteous Kill

Police psychologists review recordings of a man (Robert De Niro), who states his name as Detective David Fisk, the "Poetry Boy" killer. The Poetry Boy earned the moniker for his modus operandi of murdering criminals and leaving short poems with their bodies. Fisk reveals that he looks up to his partner of almost 30 years, Tom Cowan (who the audience is led to believe is the character portrayed by Al Pacino), and considers him to be his role model of how a cop should be. Pacino's character is known by the nickname "Rooster" and De Niro's by "Turk," and they are referred as such outside of the recordings.
These recordings provide a narrative, and the film opens with the tenth victim, a drug dealer named Robert "Rambo" Brady (Rob Dyrdek). Turk and Rooster investigate the murder with the less-experienced Detectives Corelli (Carla Gugino), Perez (John Leguizamo), and Riley (Donnie Wahlberg). When they find a poem on the body, they link it to the Poetry Boy.
As Poetry Boy murders acquitted rapist Jonathan Van Luytens and Father Connell, a Catholic priest and child molester (whose victims included Poetry Boy himself), tension builds between Turk, Corelli, and Perez. Turk is now living with Corelli, who happens to be Perez's ex-girlfriend. Poetry Boy assaults an attempted fourteenth victim, Russian mobster Yevgeny Magulat (who survives), and goes on to shoot at Perez's house and rape Corelli. Perez and Riley suspect Turk of being Poetry Boy due to his markmanship skills and psych evaluations, so they arrange a secretly supervised meeting between Turk and a drug dealer Marcus "Spider" Smith (50 Cent), during which Turk supposedly must kill him. Turk proves his innocence during an encounter with this drug dealer as he has the "wrong" gun and humiliating but obviously inappropriate poem. After Perez and Riley leave the scene unsatisfied, Rooster kills Spider. During this scrape Rooster inadvertently drops his diary.
Turk stumbles upon and reads Rooster's journal, Rooster claims Spider as Poetry Boy's fourteenth victim. Rooster puts Turk in front of a video camera and forces him to read the journal. At this point, it is revealed that the narration set Turk up as a red herring, and Rooster is the actual Poetry Boy. Turk's name is actually Tom Cowan, and Rooster is David Fisk. Rooster lost his faith in justice when Turk planted a gun at the house of acquitted child molester and murderer Charles Randall (Frank John Hughes), convicting him. This leads him to take justice into his own hands.
When Turk finishes, he chases Rooster to a construction site. Rooster fires aimlessly to convince Turk to report that the Poetry Boy is assaulting a police officer, resisting arrest, and fleeing, but Turk resists. When Rooster takes aim at Turk, Turk fires, striking Rooster in the chest. He calls for an ambulance, but Rooster begs him to call it off and let him die. After some hesitation, Turk calls off the ambulance, allowing Rooster to bleed to death. He is last shown coaching a Police Athletic League baseball team as Corelli looks on.

Question: Who is the acquitted child mollestor and killer ?
Answer: Charles Randall is the acqutted child mollestor and killer.