PHILADELPHIA (WPVI) -- Police departments across the country are on alert, including here in Philadelphia, as the new movie "Joker" hits theaters.
A typical night at the Regal UA Main Street Theatre in Manayunk doesn't include three patrol cars and a counterterrorism unit on guard. But Thursday night wasn't your typical debut.
"Joker" with Joaquin Phoenix has been highly anticipated.
Mike Kern of Manayunk said, "He's a guy who thinks the concept of crime is funny-- I love it."
But the film has also come under high scrutiny for its violent content and what that might inspire.
ABC News confirms the FBI has received tips of threatening posts on social media calling for "unspecific mass shootings" linked to Thursday's release.
That's prompted a city-wide response by the Philadelphia Police Department.
Captain Malachi Jones said, "What happened back in 2012 in Aurora, Colorado, there's a heightened sense of concern and people naturally didn't forget that. There could be a repeat out there. The fact is we don't know."
"The main thing is we have no viable threat that currently is going on," he said.
But Jones said there is a plan in place while the movie is in popular demand to keep things safe across city theaters.
"What we plan to do, again, is a precautionary measure - police officers at the theaters to make people feel comfortable," Jones said,
Most "Joker" fans at the Manayunk theater were aware of the concern and appreciated Philadelphia police keeping out an eye.
Dwayne Martinez of North Philadelphia said, "Philly is a great city. City of Brotherly Love. I don't think anything bad is gonna happen here."
Griffin Henry of Manayunk said, "It's nice to know there are cops here, but you got to live your life and do what you got to do."
'Joker' movie premiere prompts Philadelphia police to increase security