They often have complex characters. The heroes are not always the traditional, morally upright ones. They might have a code of their own that is different from the general society's norms. For example, they could be involved in illegal activities but still have a sense of loyalty and justice within their own group.
The Gangster Squad is not based on a true story. It's a work of imagination by the filmmakers to present an engaging crime drama. The characters and events are made up to captivate the audience.
Citizen Gangster is not based on a true story. It's a work of fiction that takes inspiration from various elements but doesn't draw directly from real-life events or people.