I don't doubt the dangerous neighborhoods described in the posts. Violent crime is concentrated in those types of neighborhoods. Still, I disagree that we should be fatalistic towards the possibility of being a victim of violent crime. From my personal experience, I believe that being touched by crime, whether as a perpetrator, victim, or witness, is more a factor of one's behavior than where one is or any other factor. We can influence crime. This belief has been confirmed over the years by both criminals and law enforcement.
I remember a rookie cop in some TV documentary who was surprised that EVERY call that he had been on (he worked the over-night shift) that resulted in an arrest involved ALCOHOL. A security guard trainer giving a talk on substance abuse said that 95% of the people whom he detained when he was a security guard were high on something. Friends and acquaintances who had relatives in jail said that one or another person got drunk, did something stupid, hell broke loose, and everyone got arrested. As someone posted below, the drug trade attracts lots of people who will be very violent to protect their money and turf. The thing is that anyone can avoid getting too close to drugs, to people who use drugs, or to people who trade in drugs. Doing that severely reduces your likelihood of getting touched by crime, regardless of where you are.
I feel that only crime we really need to worry about, because we can't easily avoid it, is that done by the mentally ill. You never know when a sick person close to the edge, will finally go over and seriously hurt a lot of people. The worst crime situation is a mentally ill person who self-medicates with drugs and has easy access to guns.