You're changing the subject.
Also, the UK has famously saturated their streets with CCTV. It's unclear how effective that's been. For a nation whose subjects often criticize the militarization of US policing, their armed police and CT police in major cities look like black- and grey-suited cop-SAS operators, sometimes driven around on the backs of motorcycles (which, admittedly, is kinda cool). And I've noticed that even with CCTV, crime's not great, though it doesn't hurt that the locals there seem to complain less about privacy than we do here.
To your question: if we want things to be better without constant patrols, we need enforcement: early, often, and vigorous. NYC cleaned itself up from what it was to how it was when I lived there (I can't speak to today). Other cities can, too. Hammer the offenders — don't give them the kid glove treatment and then apologize for how their unfortunate circumstance in life really makes this all the victim's fault. Give them some Quiet Time behind bars to reconsider their life's choices. Give 'em the tough love they didn't get as children. It's pretty much too late to fix a blown childhood because their parent wouldn't read to them, at least until offenders age out naturally. When are we going to get realistic?
That said, what with The City's leadership and the habits of our fellow voters, I fear Union Square is going to empty out even more and our economy will continue to hemorrhage dollars towards no real effect (except good feels). And life will get measurably worse for our service industry workers and many others.