las vegas and other major u.s. cities. police in vegas say they tike the threat seriously. what else are they going to do? and they're stepping up security. we won't show the videos, but trace gallagher with more. what else do we know about the this? >> shep, it was narrated by an american jihadist. he called for targets in russia and las vegas. they believe the video is somewhere back in 2015 but it would be irresponsible to dismiss the threat, especially in the wake of the manchester arena attack and the fact that very gas is a big event designation with concert venues and thousands of people walking around at any given moment. when you have this isis propaganda video and last week's worning from homeland security calling this the most serious threat environment since 9-11,