There are some pretty sobering statistics regarding abortion and crime, that being the reduction of the crime rate due to abortion. It would appear that those of us on the bottom of the economic scale, who are more likely to have an abortion, unwed mothers, teen pregnancies and the like, their children, alledgedly are more at risk and are predisposed to a life of crime.
With the irresponsible actions of socially damaged teen parents, not yet being in a position of power to effectively rear thier children, being not more than children themselves, their offspring have a tendency to go un-monitored and un-checked, allowed to run wild in the streets at a very early age, while often, their underage, unwed mothers, continue to try and live the lifestyle that got them pregnant in the first place, or at best chooses not to do anything constructive with her life.
If that be the case, with the termination of the pregnancy of many of theses potential problems of society, the crime rate goes down. They didn't get the chance at becoming a problem. They also never got a chance to become part of the solution, either. We can roll the dice all we choose, but we may never truly know.
For a look at both sides of the story, check here
http://www.ncpa.org/pi/crime/pd082599g.html