I wrote in another comment but basically yes. Also they can focus on other cases that require physical presence. No need to patrol the entire subway, put 100 police officers to just patrol, every station when you can have 2-3 guys watch the cameras and just 2-3 patrols ready for intervention.
Because it’s hard to investigate that with old cctv tech. Unless the person on the video was easily identifiable, it’s hard to do anything to follow up. With the new networked AI tech you could search for the person across the whole network to find out where they went / get a better view of them.