* Denver killings cast pall over big-budget movie and Hollywood
* "Dark Knight Rises" starts well at box office, but can it last?
* Theaters tighten security, studio pulls back promotions
* Celebrities tweet sympathy, sorrow and in some cases, anger (Adds canceled international appearances, paragraph 17)
By Bob Tourtellotte and Ronald Grover
LOS ANGELES, July 20 (Reuters) - Hollywood and its storied Warner Bros. studio on Friday faced sharp scrutiny and the prospect of seeing blockbuster "The Dark Knight Rises" sink at box offices following a killing spree in Colorado that could test fan appetite for violent films.
Warner Bros., a unit of Time Warner Inc, saw its big-budget film take in a near record $30.6 million in midnight screenings on Friday, but ticket sales were overshadowed by the shooting. As news spread through the day, the film's director, Christopher Nolan, expressed his "profound sorrow" at the rampage that took the lives of 12 people and injured 58 more.
While the studio did not cancel any of the movie's planned screenings, it did stop many promotions and some TV networks stopped running advertisements for the movie.
Theater owners and police from New York to Los Angeles beefed up security to assure people that the movies - a place to escape troubles and be entertained - were still safe.
The head of Cinemark Holdings, owner of the Century 16 movie theater where the shooting occurred in Aurora, Colorado, went on TV to stress the safety of moviegoing. Cinemark CEO Tim Warner called the shooting "a one-off tragedy."
"We play to 250 to 255 million people a year with very little incidents. As so, the movie theaters are a very safe and secure environment," Warner said on CNBC.
"The Dark Knight Rises," based on the exploits of crime-fighting superhero Batman, is one of this year's major movie releases. Some box-office watchers had believed its U.S. and Canadian ticket sales could reach as high as $198 million over this debut weekend, just shy of the $207 million opening set by "The Avengers" earlier this year. The movie cost Warner Bros. $250 million to produce and tens of millions more to market.
But at a midnight premiere in Aurora, a suburb of Denver, a gunman wearing a gas mask and a bulletproof vest hurled a gas canister inside the theater and opened fire on moviegoers.
"The movie theatre is my home, and the idea that someone would violate that innocent and hopeful place in such an unbearably savage way is devastating to me," Nolan said in his statement. "Nothing any of us can say could ever adequately express our feelings for the innocent victims of this appalling crime, but our thoughts are with them and their families."
Hollywood box-office watchers said it was too soon to know exactly how ticket sales would be affected by the event because the industry had never faced a situation like this one.
"It's too early to tell. This is a tragic and unprecedented event," said Paul Dergarabedian, box-office watcher for Hollywood.com Box Office.
Others said the killings might do little to dampen turnout for "Dark Knight Rises," the finale to a popular Batman saga.
"As horrible as this was, it is likely to affect 'The Dark' at the edges and won't take away that many viewers," said Tony Wible, an analyst with Janney Montgomery Scott, who follows entertainment companies and theater chains. "There are only a few people who won't come out to see a movie because of this."
Some industry experts, including former Columbia Pictures marketing head Peter Sealey, said the studio should scale back its promotion of the film, and with strong advance word-of-mouth publicity, it might not even need to advertise in order to bring in big numbers at the box office.
"Warner Brothers should show sensitivity and pull the ads for a week, certainly in Denver, and maybe around the country," said former Columbia Pictures marketing head Peter Sealey.
Phil Contrino, editor of Boxoffice.com, said the impact could go beyond just "The Dark Knight Rises" to all films in theaters if people stay away, and it could extend well into the future if the event lingers in people's minds.
Indeed, Hollywood and the movie industry have faced real-life horrors before and shown sensitivity. On Friday, Warner Bros. pulled a promotion for a mob film "Gangster Squad" from theaters, canceled a "Dark Knight" premiere in Paris, called off app e arances by the cast in Mexico and Japan, and said it would not post any more box-office figures until the weekend passed.
"Warner Bros. and the filmmakers are deeply saddened to learn about this shocking incident. We extend our sincere sympathies to the families and loved ones of the victims at this tragic time," the company said in a statement.
Earlier this year, Warner pulled video ads for 9/11 film "Extremely Loud and Incredibly Close" around Ground Zero in New York after residents there complained it was insensitive.
In the wake of those attacks back in 2001, promotional posters for Sony Pictures Entertainment's "Spider-Man" were changed to remove images of the World Trade Center towers.
Back in 1991 at the premieres of gangland crime drama "Boyz n The Hood," one man was killed and many injured when random violence erupted in several movie theaters across the United States, forcing some venues to cancel screenings.
While much of Hollywood remained quiet in public, some stars, including former California governor and actor Arnold Schwarzenegger, comedienne Ellen DeGeneres, "American Idol" host Ryan Seacrest and film director Kevin Smith took to Twitter to express shock, sorrow and in some cases, anger.
"A mad man has shattered lives forever in Colorado. To everyone who helped folks get to safety in that theatre THANK YOU for your bravery ... Hearts and Prayers to all affected by the craziness in Colorado," Whoopi Goldberg tweeted.
VIOLENCE IN MEDIA
In the days and weeks to follow, the shooting will likely renew calls for ways to reduce violence in movies and people will point to Hollywood as being, in some ways, responsible for Friday's deadly shooting spree.
Carole Lieberman, a Beverly Hills media psychiatrist who specializes in the impact of media on people, thought it was likely no coincidence that the suspected gunman, 24-year-old James Eagan Holmes, picked the "Batman" movie with its violent tale of good versus evil to carry out the deadly shooting.
"It's tragic, but we're going to find out that he has been exposed to significant amounts of media violence in his past," she speculated.
The National Association of Theatre Owners, a trade industry group representing movie theater owners, said its member companies were "working closely with local law enforcement agencies and reviewing security procedures."
AMC Theaters, one of the largest chains in the United States, said it would not allow guests to wear face-covering masks or take fake weapons inside its buildings.
Carmike Cinemas, the nation's fourth-largest theater chain, said it was using uniformed "law enforcement officers and plainclothes agents" at its 237 theaters.
Shares of movie theater chains dropped on Friday after the killings. Cinemark Holdings, declined 4.6 percent to close at $23.15 on the New York Stock Exchange. Regal Entertainment Group shares fell 4.4 percent to close at $13.54 on Nasdaq. Shares of Carmike slipped 2.3 percent to $14.48, also on Nasdaq.