Why doesn't the police just check traffic light surrveilance cameras?

This is probably a pretty stupid question, but wouldn't it be a lot easier if they just looked at those cameras and knew everybody's movements?

I mean, let's say a murder occurs somewhere. Can't they just check the cameras and see where the car went and immediately find the murderer?Why doesn't the police just check traffic light surrveilance cameras?
people would start breaking the camerasWhy doesn't the police just check traffic light surrveilance cameras?
in my town there are cameras at every light, people will sit at the red light and then just take off when its still red, no one checks whats on the cameras, there is no reason to have the camerasWhy doesn't the police just check traffic light surrveilance cameras?
They are very poor quality cameras. Like security cameras. no matter how much you zoom in, you can't see diddly, other than, oh ya a big guy stole that car. Or that woman was raped by something or someone.

Somebody needs to make an awesome, yet cheap camera that you can actually see stuff with.

Traffic cameras are only calibrated to see the license plates on the lane ahead of them.
Cameras aren't located at every stop light or street light. Furthermore, most murderers don't run away in cars. They escape on foot, or in some other way that is difficult to detect.