The civil trial related to the Aurora Theater shooting begins on Monday.

Twenty-seven families are suing Cinemark, the company that owns the Century 16 Theater in Aurora, for what equates to "lack of security," according to Marc Bern, the attorney representing the families.

The lawsuit states the theater chain is being sued for a variety of security issues, including:

Not hiring extra security on the night of July 20, 2012 despite having hired extra officers on previous Friday and Saturday nights

Not having alarms on the emergency exit of the theater (although, the theater responded to this claim saying that the exit was not an "emergency" exit)

Allowing a door to be propped open, so that the shooter could return to the theater

No surveillance in the back of the theater

Employees and security not intervening during the shooting

Bern is a guest on this week's Politics Unplugged. During a recorded interview to air Sunday at 4 p.m. on Denver7, he described a warning that theater chains received from the Department of Homeland Security on May 17, 2012.

"There was a warning more than two months before [the Aurora Theater shooting], the Department of Homeland Security sent out a notice, called a 'Roll Call Release,' that said that movie theaters in the United States were targeted by terrorists," said Bern. "Now this shooter was as good as any terrorist, whether it was ISIS or just this individual, who came in to terrorize and kill individuals."

He intends to use that document as evidence in the trial that begins with jury selection on Monday.

The alert, titled "Terrorists’ Interest in Attacking Theaters and Similar Mass Gatherings," warns about the potential for a theater attack after a suicide bombing in a theater in Somalia in April 2012:

"Although we have no specific or credible information indicating that terrorists plan to attack theaters in the United States, terrorists may seek to emulate overseas attacks on theaters here in the United States because they have the potential to inflict mass casualties and cause local economic damage."

"This Homeland Security warning, 'Roll Call Release,' was sent to an organization called NATO, the National Association of Theater Owners, that was then sent to various chains and their upper management and in this case it stayed there," said Bern. "The upper management received it, but did nothing with it to warn the various theater general managers and their immediate supervisors."

Denver7 reached out to NATO, as well as Cinemark, Regal and AMC Theaters, to find out what happened after this warning was received, but none of the organizations answered our question.

An online search reveals multiple "Roll Call Releases" warning about:

IEDs in Human Remains

Using the Internet for Attack Planning

Threats to Android Devices

Use of Motorcycles in Suicide Attacks

A former federal law enforcement supervisor told Denver7 that he is not a fan of "Roll Call Releases" because they provide little specific information.

"What is the appropriate response to this thing? It doesn't tell them what to do," said the federal law enforcement source.

The civil trial against Cinemark is expected to last three weeks.

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