Highly unlikely the two incidents are related.
The police are not going to interfere with ATC tower operations particularly at critical altitudes near the runway.
Like the previous post suggests, if law enforcement relays the request to ATC that they need time to set up an operation; there is plenty of real estate on the ground they can be held at. I never have heard of this happening, but in theory they could contact United or the en route controlling ATC center and hold at altitude as well.