Wow. Where did this happen, and how many people were killed? There's also this one: http://dropitanddrive.com/2011/10/11/i-just-learned-how-to-text-message/
No survivor on that. I have seen so many like this posted from Russia on Live Leak. For the most part they were mostly caused by stupid careless drivers.
A lot of the dash cam footage on the net is from Russia, because staged accidents and insurance fraud are rampant. http://www.youtube.com/watch?v=-hevlOp2S1g
So the first video posted above is not from a "state trooper cam" Might have to get me a dash cam though. A lot of cyclists around here are starting to get helmet or handlebar cams, since the legal system almost always finds in favor of the motorist otherwise.
I would say its definitely not from a law enforcement dash cam. Law enforcement cams are stamped on the video the time, date, speed, and on/off status of the lights & sirens.