interestingly, many sociologists believe that the relative decline of crime rates in recent years is the direct result of the Roe vs. Wade decision. Because if you seriously don't want your child, you're not going to raise them well. Children that would be aborted are more likely to become criminals than wanted children. Parents who would consider abortion generally aren't ready to be parents, whether it's for economic, social, or lifestyle reasons.
That guy's statement certainly oversimplifies that ... but the vast majority of violent crime comes from the bottom tier of the socioeconomic ladder, and even today you'll find an overrepresentation of blacks there (or rather, an underrepresentation of blacks in the middle and upper classes).
I think the point he was trying to make was that if you want to end crime, you should abort all the children who would be born at or below the poverty line. But you'd be "throwing out the baby with the bathwater" so to speak, because a lot of great people come from lousy places. I think it's more important to address the causes of poverty than the results of it, y'know?