Updated at 5:40 p.m. ET

The company that owns the Mandalay Bay Resort and Casino in Las Vegas has asked federal courts to declare that it is not liable in the October 2017 mass shooting carried out by a gunman staying at Mandalay Bay.

Stephen Paddock stayed at the resort for several days before he opened fire on the Route 91 Harvest music festival. Aiming from the windows of his 32nd-floor hotel room, he killed 58 people and injured hundreds.

Many of those victims have since filed lawsuits in state court.

Now, MGM Resorts International, which owns Mandalay Bay and the concert venue, and several of its associated companies have filed lawsuits against victims, asking federal judges to step in and declare the resort company free from liability.

The lawsuits were filed on Friday; the Las Vegas Review-Journalreported on them Monday night.

"No MGM Party attempted to commit, knowingly participated in, aided, abetted, committed, or participated in any conspiracy to commit any act of terrorism," the lawsuits state.

The lawsuits name more than 800 defendants in California and more than 200 in Nevada.

The defendants are victims of the shooting who have threatened lawsuits against MGM Resorts and its associated companies or have brought lawsuits that have since been dismissed, MGM writes.

In the lawsuits, MGM Resorts says that a security company at the concert provided a variety of services designed to prevent mass violence, and that those services were certified by the Department of Homeland Security as appropriate. As a result, the hotel has no liability, MGM Resorts says.

The lawsuit cites a 2002 federal law designed to encourage companies to deploy anti-terrorism "security technologies" without fear of being held responsible for damages if a terror attack happens anyway.

In a statement emailed to NPR, a spokeswoman for MGM Resorts said federal court was "an appropriate venue" for the cases, given the federal law.

"While we expected the litigation that followed [the attack], we also feel strongly that victims and the community should be able to recover and find resolution in a timely manner. ... Years of drawn-out litigation and hearings are not in the best interest of victims, the community and those still healing," Debra DeShong said.

Route91Strong, a nonprofit started by survivors of the shooting, issued a statement saying that its leaders are "deeply saddened" by news of the lawsuit.

"Rather than supporting victims, MGM is re-victimizing them," the group said. "This is not helping survivors heal, and it is not helping Las Vegas heal."

"We collectively view this as a bullying tactic to intimidate the survivors who are rightfully seeking social change and redress through the litigation process," said co-founder Brian Claypool. "We don't believe that MGM will prevail on its lawsuit and this hypocritical maneuver will end up being a public relations nightmare for MGM."

Co-founder Lisa Fine called the lawsuit a "bump in the road to recovery."

As NPR's Kirk Siegler reported shortly after the shooting, victims face a tough legal battle in attempting to hold the hotel liable:

"[I]f recent mass shootings are any indication, proving negligence in cases that target venues is difficult, according to Tom Russell, a personal injury lawyer and law professor at the University of Denver.

" 'One would have to show that the hotel had knowledge about this of some sort and they disregarded it,' Russell said. 'It would require that level of knowledge.'

"One of the most high profile – and only – recent related cases occurred in Russell's backyard, following the Aurora movie theater massacre in 2012. Victims tried to sue the theater chain, Cinemark. They lost, and were even ordered to pay the company's legal fees. Russell says venues themselves can often be victims, too, in the form of lost business and other harm.

" 'One can't blame the hotel for not predicting that this gunman would go up to their 32nd floor with an arsenal and break out the windows and start firing at people,' Russell says."

Lawsuits attempting to hold gun manufacturers liable for mass shootings have historically not been successful, either, Siegler reports.

Amara Omeokwe contributed reporting to this article.

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