There is also a difference in the way you interpret the data.
Redlight and speedcams work very precisely because each vehicle has a license plate, matching an entry into a vehicle database.
Either you have a matching number, that should match an exact vehicle (or a counterfeit license plate), or you don't.
Identity is binary.
Also the devices are usually calibrated to guarantee precise results regarding measurement.
in other words, you can at least reliable trust the information (platenumber ; speed) coming out of photo by a speed-cam
(then, whether the license plate matches the actual car or was tampered with, and whether the car's registered owner was driving or some 3rd party, is an entirely different question)
Image analysis only give you a likelihood of resemblance.
Footage of person may or might not look like the suspect.
It has the same kind of imprecision as any visual witness. Some are better than other at identifying suspect, but nobody is perfect.
The only certitude you have is that the person doing crime on the video tape looks more or less like a given suspect.
The suspect *might be* the perpetrator.
But the suspect *might also be* a random look-alike that looked close enough to the person on the tape to fool the algorithm by chance.
That's valid both for visual clues (and that even if technologies becomes better at distinguishing people's image than regular witnesses) and for DNA clues (given a big enough pool of DNA samples, any methodology - short of full genome sequencing and that doesn't take into account twins - will eventually start to show random matches)
So information from cam can only be used as clues ("a person with a description matching the suspect has been recorded on tape to perpetrate a crime") and compared with other information (alibi: the suspect was at a party at that time and everyone else there saw him. The tape recorded a look-alike).
TL;DR: Technology is never going to replace good old detective work, only give extra information and tools.
That's unless government makes it mandatory to shave everyone's head and tatoo a QR-Code with the SSN.