As RF mentioned, Steven Paddock, who murdered at least fifty people and wounded over 400 in Las Vegas last night was involved in a legal kerfuffle with the Cosmopolitan Hotel in 2012. It appears that Paddock filed a “premises liability” complaint against Cosmopolitan in 2012, according to Court Records from Clark County, Nevada.
The complaint document itself isn’t available online. While the matter was pending in the courts, the parties submitted the case to binding arbitration to a third party mediator, and the mediator appears to have issued some sort of monetary award to the plaintiff. As a result, both parties agreed to “dismiss” the matter “with prejudice” in 2014.
In this case, with prejudice means that the dismissal is final, and the plaintiff will not be able to file another lawsuit relating to the same facts.
There’s a lot of speculation floating around in news reports and social media about the murderer and his potential motives. It doesn’t appear that this lawsuit has much to do with the attacker’s motives (a “revenge” attack or something of the sort.) However, in a heinous, high profile crime such as this, every aspect of the killer’s background will be examined with a fine toothed comb. The best advice: as always, wait until all the facts are in before ruling anything in or out.