The most accurate information may be gleaned from police scanners. News cameras may give you pictures of the amount of police officers at the scene, but they cannot get close enough to give you video of what's actually happening. The irony is that of those three sources of information (Web site, radio, news camera), the best source of "real time" information is the oldest. Yes, it's true that the scanner is being broadcast over the internet, but you could listen to the police scanner with amateur radio equipment decades ago.

EDIT: I find that it is much easier to listen to the police scanner than a news station, because the SNR ratio is much higher. When there is a break in the action, news reporters fill the air time with speculation or repeat the same old information. On the police scanner, when they have no new information, they are silent.

Having said that, I still find it cool to hear an officer ask the dispatcher (on the radio) to tell an overhead helicopter to point a searchlight at a certain location, and moments later see on television a helicopter flying overhead with its searchlight on.