The shooter in Colorado reportedly wore a riot helmet and a bulletproof vest and was dressed in black, raising questions about whether theaters should ban or limit costumes at the screenings. Many fans of Christopher Nolan's Batman films attend screenings in costume.
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The Los Angeles Police Department's Hollywood division sent officers to check on theaters, including the ArcLight, but no security issues were found, a watch commander said.
"There's nothing that suggests that there's anything sinister planned beyond what happened in Colorado," said Sgt. Enrique Mendoza, watch commander of the LAPD Hollywood division. "What happened in Colorado appears to be an anomaly, an isolated incident."
New York police said Friday they would deploy to theaters screening "The Dark Knight Rises."
"As a precaution against copycats and to raise the comfort levels among movie patrons in the wake of the horrendous shooting in Colorado, the New York City Police Department is providing coverage at theaters where the 'The Dark Knight Rises' is playing in the five boroughs," Police Commissioner Raymond W. Kelly said in a statement.
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The Warner Bros. film was scheduled to open at 4,404 theaters, including 332 Imax locations, this weekend in the U.S. and Canada — the second highest all-time behind the 4,468 for "The Twilight Saga: Eclipse."
At the AMC theater at Universal Citywalk early Friday morning, three security guards were on duty, but it was unclear whether that was normal staffing or an increase; the guards refused request for comment.
Many fans of "The Dark Knight Rises" at Citywalk early Friday were unaware of the events in Colorado. But Xochitl Serna, 36, and her 14-year-old son learned about the shooting on the news before heading to a 3:35 a.m. screening. They said the incident did not make them reconsider their movie plans.
"Right before we left I heard and I was like, 'What the ... ?' It's pretty scary," said Serna, who was wearing a T-shirt with the film's logo on it. "But I work at Universal so I knew there would be lots of security, so we decided, 'Nah, it's OK, we'll be alright.' "
The few other moviegoers who knew of the Colorado tragedy felt the same kind of event would not take place in Los Angeles.
"It's different in Colorado - that's middle America. I don't think that would happen here," said Fernando Lopez, 25, who heard about the shooting 20 minutes before the 6:40 a.m. screening.
"Everybody shoots each other in Colorado," added Abigail Keever, 25, who was about to head into the same screening.
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Staff writers Andrew Blankstein and Matt Donnelly contributed to this report.