By CBS3 Staff

PHILADELPHIA (CBS) – A new film in theaters is generating a lot of attention from both moviegoers and law enforcement officials. Ahead of the release of the new “Joker” movie, the FBI issued a warning telling police departments nationwide about online threats of mass shootings at theaters showing the film.

The “Joker” hit theaters on Thursday night and Eyewitness News was at AMC Broadstreet 7 in North Philadelphia where fans flocked to watch the premiere.

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“That’s going to be ‘Movie of the Year.’ I’m calling it right now,” one fan said.

The movie dives into how a middle-aged man, played by Joaquin Phoenix, becomes the Joker. His internal struggles turn into acts of violence.

“He [actor Joaquin Phoenix] was terrifying in that but like in a good way,” another fan said.

Moviegoer Martin Rodriguez who saw the film says, “If you’re looking for a movie where it’s all happy-go-lucky at some point, it’s not the case. It’s very dark and at the same time it gives you a little sentiment to the way he [the Joker] became who he was.”

The movie is raising concerns about mental health and gun violence, and potentially inspiring yet another mass shooting.

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The increased sense of concern surrounding the movie’s premiere is due to the mass shooting at a movie theater in Aurora, Colorado in 2012. That shooting left 12 people dead and 70 injured and happened during the premiere of another Batman movie, “The Dark Knight Rises.”

Eyewitness News spoke to fans over the safety concerns surrounding the film.

“It was definitely frustrating that the media hyped it up so much and talked about that because it definitely put it in your head,” moviegoer Laura Holliday said.

Although there was not a heavy police presence at the AMC Broadstreet 7, that doesn’t mean safety wasn’t a concern for authorities or moviegoers.

Those affected by the mass shooting in Colorado sent a letter to Warner Brothers urging them to lobby for gun reform. Meanwhile, Warner Brothers has said their film does not endorse violence.

The debate will continue as we head into the opening weekend.

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Reporter Crystal Cranmore contributed to this report.