New York used to be very, very bad. People thought that was just life in the big city. Then they decided to maintain order, even painting over graffiti as soon as they found it, and enforced even minor laws. The criminal element perceived that bad behavior would not be tolerated. Malcolm Gladwell describes it in Tipping Point.
The most remarkable thing about it is how few other places have tried it since.
When people have control over whether laws are enforced where they live, they usually choose to enforce them rather than let everything go to hell.
Back in the 80's, it was crazy. I grew up in a good neighborhood in Queens. The NYPD hid the drunks and incompetents in precients that served safer neighborhoods in those days. One day, a car almost hit my friends playing stickball in the street, then proceeded to go down the block and empty an Uzi into a guy at a bus stop. (Life Lesson: Don't piss off Columbian drug dealers.)
So my dad calls the cops. He dials 911, and the cop asks "Are they still shooting?" and hangs up when my dad says "Uh, no". He ended up pulling the fire department call box out on the street, and the firemen called for cops over the radio.
As much as I love how safe NYC is, I don't want it to turn into Singapore.
Crime happens when the risk of getting caught times the cost of punishment is lower than the benefit of the crime. If you increase the risk of getting caught, you may safely (in fact, you should) decrease the cost of being punished.
For example, people throwing plastic bags everywhere. Now were trying to restrict the freedom of people who don't litter rather than holding responsible those causing the problem.
http://en.wikipedia.org/wiki/Broken_windows_theory#Criticism...
See http://gladwell.typepad.com/gladwellcom/2006/03/thoughts_on_..., http://www.freakonomics.com/2006/03/09/malcolm-gladwell-on-t..., http://gladwell.typepad.com/gladwellcom/2006/03/levitt_and_d...
The trends you're referring to take decades. And don't seem to have worked in Oakland.
So what causes people to steal? They are poor, they want more than they currently have because what they have is not enough. If you want them to stop stealing, then society must become fairer. As it stands, resources are allocated through a sort of popularity contest. Those at the top of the social popularity ranking get the most.
Why do people kill and fight? For respect. Society looks down on the poor, it avoids them, laughs at them and criticizes them for being where they are without having walked in their shoes. Want people to stop being so violent? Show them some love and put the batons away.
Not to mention the double standard of having a bunch of hired thugs (the police) keeping us safe from a bunch of hired thugs (gangsters). I don't want any thugs in my neighborhood.