(CNN) -- The tragedy that occurred at Sandy Hook Elementary in December has left its mark on Jim Carrey.
The 51-year-old actor has said that in light of that event and those like it, he can't stand behind the violence in his upcoming movie, "Kick-Ass 2."
"I did Kickass a month b4 Sandy Hook and now in all good conscience I cannot support that level of violence," Carrey tweeted on Sunday. "(M)y apologies to others involve(d) with the film."
Directed by Jeff Wadlow, "Kick-Ass 2" is the follow-up to 2010's initial installment, which was adapted from Mark Millar's comic books. The story doesn't at all shy away from violence, featuring two teens (Aaron Taylor-Johnson and Chloe Grace Moretz) who decide that they don't need special powers to fight crime and develop their own superhero personas.
The sequel sees Taylor-Johnson and Moretz reprise their roles of Kick-Ass and Hit Girl, with Carrey signed on to play fellow crime-fighter Colonel Stars and Stripes.
Carrey said in his tweeted statement on Sunday that he's not "ashamed" of "Kick-Ass 2," but that "recent events have caused a change in my heart." When a Twitter follower asked Carrey why his change of heart didn't occur after the shootings at Columbine or Virginia Tech, the actor explained that "it did, over time."
Nonetheless, Carrey's remarks have left creator Millar "baffled."
On his website, Millar explains that he's a huge fan of Carrey, and "made a mental note" to work with him after the actor demonstrated his own fandom for "Kick-Ass." In Millar's eyes, Carrey's turn in the sequel is some of the actor's best work, making his withdrawal of support "all the more surprising."
"As you may know, Jim is a passionate advocate of gun-control, and I respect both his politics and his opinion, but I'm baffled by this sudden announcement as nothing seen in this picture wasn't in the screenplay eighteen months ago," Millar writes. "Yes, the body count is very high, but a movie called 'Kick-Ass 2' really has to do what it says on the tin. A sequel to the picture that gave us HIT-GIRL was always going to have some blood on the floor and this should have been no shock to a guy who enjoyed the first movie so much."
And then there's the fact that "'Kick-Ass 2' isn't a documentary," Millar points out.
"Like Jim, I'm horrified by real life violence (even though I'm Scottish) ... This is fiction," he continues. "Kick-Ass avoids the usual bloodless body count of most big summer pictures and focuses instead of the CONSEQUENCES of violence, whether it's the ramifications for friends and family or, as we saw in the first movie, Kick-Ass spending six months in hospital after his first street altercation."
While Millar hopes that Carrey will come around to supporting the sequel, "ultimately, this is his decision," he concluded. "I've never quite bought the notion that violence in fiction leads to violence in real life any more than Harry Potter casting a spell creates more Boy Wizards in real life. Our job as storytellers is to entertain and our toolbox can't be sabotaged by curtailing the use of guns in an action movie."
"Kick-Ass 2" is slated to land in theaters on Aug. 16.
CNN's Henry Hanks contributed to this report.
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