The "good guys" in the movie are flawed characters rooted in "noir" traditions. There are prostitutes, sexual predators, cannibal serial killers, pedophiles, men who are physically abusive to their girlfriends, a corrupt politician, corrupt priests, and corrupt police officers.
Extreme, intense, constant, and graphic violence; torture, suicide, dismemberment, references to cannibalism, child molestation, and rape. A serial killer captures women, hangs their heads on the wall as trophies, and there's talk of him eating the women. Sexual abuse of a 10-year-old girl strongly implied. A woman's hand is cut off by this serial killer; she mentions how he sucked the meat off her fingers. Frequent gore.
Female nudity. Most of the women in the movie are prostitutes.
Frequent profanity, including "s--t" and "d--k," and the use of homophobic slurs such as "fag" and "dyke."
Frequent drinking, of beer and from flasks. Cigarette smoking. Prescription drug abuse.