Good that they are on alert. You got to be pretty stupid to travel with swastikas on your vehicle and weapons inside your pickup truck into Washington, DC, kind of like have an invitation to "arrest me first". Play stupid games win stupid prizes.
I figure Capital Police aren't going to take another ass whipping by anti-American extremists anytime soon, figuring they've had enough. Push comes to shove, I figure they will defend with weapons far sooner than last time the extremists were leading the way against them and the seats of government. I hope the radicals don't launch another attack, so it doesn't come to that. If the radicals do launch another attack, I support whatever action the Capital Police have to take to defend.