Denver traffic cameras catch criminals good.

I've noticed over the last few years living in Denver, that the cops catch a good percentage of criminals on the run here. Many times I watch the news and hear about a hit and run with no witnesses, but they have a vehicle description. Many times I have been surprised with the accuracy of the vehicle description they are looking for. I know whats going on.
I have some experience with aggregating and monitoring video signals (DirecTV's HD NOC), and some experience with traffic cameras and systems (Maptuit). These observations, my experience and the fact that EVERY intersection in Denver has at least 4 cameras tells me two things: 1. All traffic cameras are being monitored and recorded (only a few are available to the public) and 2. The Denver police have access to these cameras and recordings and use them to catch bad guys.

I have found one explanation for the cameras as such:
"What is the function of the cameras on the traffic signals?
The video cameras are state-of-the-art vehicle detecting devices that tell the signal controller when vehicles are present at the intersection. These cameras replace the old loop detection devices previously located in the pavement."

Yes, they can be used for that, but the greater use of solving crimes is unacknowledged here.
The general public doesn't know the full extent of the DPD's surveillance capabilities.
It's something that has been happening in London for years. The cops can go back in time and track the bad guys back to their lair with these camera logs.

This is the only conclusion I can come to, given how many times I have seen a crime on the news that has an accompanying vehicle description.