One of the true story elements could be the sense of a community being fed up with crime. In real life, there are places where people feel that the authorities aren't doing enough to combat crime, similar to the setting in the movie. Another element might be the idea of individuals taking justice into their own hands, which has historical precedents in different forms of vigilantism.
Well, the prevalence of organized crime in the movie might be related to real - life situations. In many cities, there have been issues with powerful criminal organizations that seem to operate with impunity. In 'Boondock Saints', the brothers' reaction to this organized crime could be seen as a fictionalized version of how some people might wish to respond in real - life situations where the justice system appears ineffective. Also, the setting in an urban environment with a seedy underbelly is a reflection of real - life areas that struggle with crime and poverty.
The movie 'Boondock Saints' contains elements that are reminiscent of real - life struggles against crime. The fact that the main characters are driven by a sense of right and wrong, and they are willing to go to extreme lengths to combat what they see as injustice, is something that can be related to real - life situations where people have had enough of the status quo. The film may have drawn inspiration from real - life cases where ordinary citizens felt compelled to take action against crime, perhaps because they felt the legal system was slow or ineffective. However, the movie also adds a lot of fictional drama, such as the elaborate crime - fighting methods of the brothers, which are not based on specific true - story details but rather on the filmmakers' creative vision.