The cruiser cam is limited in a very practical sense - there are only as many out there as there are cruisers. You can't blanket the city with them without blanketing the city with cruisers. You can't use them to track everybody everywhere without spending too much money and scaring the straights.

A cruiser cam is equivalent to a cop seeing things that happen in public.

Not only that, they encourage professionalism and acceptable behavior on the part of the police. Sure, they can be turned off, but the officer's testimony is so much more compelling when there is video.

I suppose the software could be used, and the database built, on the images anyway. But considering the limited resources, it is likely that the cameras will be focused on problems, not fishing for crimes.