Despite a common practice, Aurora cinema lacked security officers the night of the Batman shooting

The movie theater in Aurora, Colo., that was the site of the mass shooting earlier this month did not have a uniformed security officer on duty, despite the fact its owner had security officers in place at other theaters offering the midnight screening of the new Batman movie, according to the Associated Press.

Plano, Texas-based Cinemark often hired off-duty police officers to work at the Aurora theater on busy Friday and Saturday nights, Aurora Police Chief Dan Oates told the AP. However, Oates said the theater had requested none for the midnight screening on July 19, which was a Thursday night.

Though Cinemark officials will not comment on its security operations, the AP was able to identify theaters around the country—including  Beaumont, Texas; Lake Charles, La.; and Tupelo, Miss.—that did use armed security officers for the midnight Batman screenings. Cinemark has 298 theaters in 40 states.

However, it's not clear whether a uniformed security officer would have been able to prevent the suspect who opened fire on the crowd of movie-goers, killing 12 and injuring more than 50.