Hnn, I don't know whether I should get involved in all this, but I'm going to anyway.
From my view, we tend to seperate people who are criminals, sexual or theft type, from the rest of the population as if they are completly different people. From this view it follows that we should be able to preempt crimes as those who perform them were going to anyway.
Ugh, this is why I'm kind of loathe to comment, it's difficult to express my views accurately through text.
Plowing on. I'll use the example of surveillence cameras. These were implemented to curtail crimes, catching people when they're performed as well as keeping watch over an area to discourage crime. As far as I can tell this hasn't had as great an impact on crime prevention as people thought, and I would hazard a guess that this is because they're generally ignored. Due to that, more people are caught after the crime, but the prevention of crime in the first place is not something they stop.
From that, the logical path would be to keep tabs on everyone so they can perceive crime before it's even perpetrated. That is a less than feasable or desirable action, because everyone is now a suspect.
If you read the above, then I might say that my view is that there's not much you can do to prevent crime with police or like, other than deal with it when it occurs. Now, don't follow the train of thought that I'm suggesting that then we shouldn't do anything, because I've had that happen before, and it's a rather unfair dismissal.
Now, I would suggest that the rise in crime is due to the increase in population. (a larger population means that there's a greater percentage of people who would perform crime, but that isn't specific people. Factors might contribute it, but it's down to the individual person to decide). This increase in population has meant that there is less of a community amongst neighbours. This drop in community would mean that there'd be less self policing, if that makes sense. If people know each other, than they can evaluate peoples personalities and judge those who are likely to do such things before they do.
It's difficult to foster a community over an entire city, thus we tend to see such closeknit communities in small villages, or in direct neighbours in a street. There is a lot of distrust protrayed over the news and media that makes people paranoid about going out and talking to each other, this would contribute quite heavily to the loss of community. People don't talk because they are suspicious of those they don't know.
Blah blah blah, has that all made sense? I hope people aren't going to judge me completely on a few sentences of musing.