These are excerpts from what could be considered the source for the Broken Windows theory (emphasis added):
[A]t the community level, disorder and crime are usually inextricably linked, in a kind of developmental sequence. Social psychologists and police officers tend to agree that if a window in a building is broken and is left unrepaired, all the rest of the windows will soon be broken. This is as true in nice neighborhoods as in run-down ones. Window-breaking does not necessarily occur on a large scale because some areas are inhabited by determined window-breakers whereas others are populated by window-lovers; rather, one unrepaired broken window is a signal that no one cares, and so breaking more windows costs nothing. (It has always been fun.)
In the theory, this "not caring" signal escalates further and further until it becomes likely that serious crimes are as inevitable as one broken window leads to all broken windows.
The unchecked panhandler is, in effect, the first broken window. Muggers and robbers, whether opportunistic or professional, believe they reduce their chances of being caught or even identified if they operate on streets where potential victims are already intimidated by prevailing conditions.
The solution presented in the original article is one of foot patrolling (as opposed to patrolling in vehicles); the community's interaction with a police officer on foot encourages a sense of security that counters feelings of "no one cares." This, in turn, helps the community as a whole avoid the Broken Windows of drunks, gang members or prostitutes.
I am not so much interested in the foot patrolling aspect of this article. Rather, I am interested in the concepts of crime escalation and prevention with regards to activities seen as petty crimes. This is the broad form of my question: Is there any evidence for or against the Broken Windows theory with regards to preventing such an escalation in crime by addressing the beginning phases of the escalation?
A slightly more focused question: Is there any correlation between action taken against petty crimes and the prevention of future serious crimes within the same community?