The Boondock Saints is all about perception. The film tells the story of fraternal twins Murphy and Connor MacManus (Norman Reedus and Sean Patrick Flannery) who, after killing two mobsters in self-defense, believe they’ve received a “calling” from god to rid the city of Boston of all its bad guys. Whether they are crazy murderers or the best thing that ever happened to Beantown is up to the audience, and FBI agent Paul Smecker (played by a scene-stealing Willem Dafoe). Make up your own mind about the MacManus brothers with these 10 fascinating facts about the 1999 cult classic.

1. THE SCRIPT WAS INSPIRED BY SEVERAL REAL-LIFE EVENTS.

Writer-director Troy Duffy based the story for The Boondock Saints on things he saw when he was working as a bartender in Los Angeles, including watching a drug dealer steal money from a dead body. The film also opens with the story of Kitty Genovese, a young woman who was murdered in Queens in 1964 and whose story has become a bit of an urban legend after it was widely (but inaccurately) reported that, despite her cries for help and dozens of witnesses, no one came to her rescue.

2. THE MOVIE WAS ITS OWN RAG-TO-RICHES STORY. 

In 1997, Duffy was working as a bartender in Los Angeles at the same time he was trying to sell his script for The Boondock Saints. The media loved the idea of a local bartender who had written what might be Hollywood’s next great film, leading the screenplay to spark a bidding war between major studios. The war ended when Miramax’s Harvey Weinstein showed up at J Sloan’s, the bar where Duffy worked, to offer him a reported $300,000 for the script and promised to buy the bar for Duffy.

3. TROY DUFFY WAS HIS OWN BIGGEST OBSTACLE IN GETTING THE FILM MADE.

Like most artists, Duffy had a very clear vision for the film. This led to some contentious meetings with potential collaborators, including getting into an argument with Ewan McGregor over the death penalty during their first meeting. Duffy’s volatile personality ended up costing him his deal with Miramax, leading him to have to shop the film around to other distributors. Eventually, the film was picked up by Franchise Pictures, despite the negative chatter now surrounding both Duffy and his movie.

4. A POPULAR DOCUMENTARY WAS MADE ABOUT DUFFY’S RISE AND FALL.

In 2003, filmmakers Tony Montana and Mark Brian Smith released Overnight, an unflattering portrait of the Duffy’s meteoric rise and fall. Though the documentary was made with Duffy’s cooperation, he (unsurprisingly) was not pleased with the final result. When asked whether he thought the portrayal of him in the film was fair, Duffy responded:

“Absolutely not. I don’t have to feel, I know, I was there, it was me it was happening to. That type of behavior that you saw in that film was the exception and not the rule. And I don’t think it was too fair of them to not provide any context of why is Troy upset, who’s he even talking to, what’s the situation. It was basically ‘Show me acting like an a**hole.’ After three years of shooting that would be a fairly easy thing to do. And through especially three of the most tumultuous years of my life.”

5. THE FILM’S THEATRICAL RELEASE WAS LIMITED FOR A VERY SERIOUS REASON.

The movie opened on U.S. screens on January 21, 2000, but it was shown in just five theaters and for one week only. The country was still reeling from the massacre at Columbine High School less than a year earlier, and 108 minutes of men who are open to killing any person they consider evil wasn’t the most popular concept with audiences. “Two boys dressed in black trench coats with guns hit a little too close to home,” actress Julie Benz, who played Special Agent Eunice Bloom in the sequel, told The New York Times in 2009.

6. CRITICS HATED THE MOVIE.

The Boondock Saints was panned by critics. Rotten Tomatoes, where the film holds a 20 percent rotten rating with critics, describes the film as “a juvenile, ugly movie that represents the worst tendencies of directors channeling Tarantino.”

7. THE CATHOLIC CHURCH HATED THE MOVIE, TOO.

The amount of violence in the script made it almost impossible for the filmmakers to find a church that would allow them to shoot on its premises. The church where the brothers attend mass in the opening scene is Boston's Union United Methodist Church. Duffy also allegedly received a letter from the Archdiocese of Toronto that detailed the church’s hatred of the film and called Duffy the “spawn of Satan.

8. AUDIENCES, ON THE OTHER HAND, LOVED THE MOVIE.

The film made almost no money during its very brief theatrical release, but sales of the DVD took off. Eventually, the movie managed to pull in $260 million in worldwide theatrical and DVD sales, largely due to positive word-of-mouth, and cemented the film’s reputation as a cult classic. In 2009, a sequel—The Boondock Saints II: All Saints Day—continued the MacManus brothers’ story.

9. A THIRD FILM IS PRETTY MUCH CONFIRMED.

When asked whether a third film might be coming during a Reddit AMA last December, Norman Reedus, who played Murphy MacManus (and, more famously, is The Walking Dead’s Daryl Dixon), responded, “Yeah it’s on. In the works, happening.” Though no official announcement of it has been made, that hasn’t stopped some outlets from reporting on what it might look like.

10. THE MACMANUS BROTHERS MIGHT ALSO BE HITTING THE SMALL SCREEN.

In addition to the third film, Duffy is also in talks with IM Global Television to create a series that would serve as a prequel to the movies. The show will focus on the lives of the brothers in South Boston in their pre-vigilante days. Reedus and Sean Patrick Flanery probably won’t return as the stars, but they may come on board as executive producers.