There are a few reasons. An important but unfortunate one is that these areas have not received toxic chemical remediation. It is common for adults and children

There are a few reasons. An important but unfortunate one is that these areas have not received toxic chemical remediation. It is common for adults and children to have complications from lead exposure. A side effect of developmental impairment is increased aggression. But there are reasons related to a different social culture. The cops and justice system can't help you and may very well ruin your life if you try to involve them, so it's easiest to kill people who slight you. These interactions happen because whatever small amount of money or credibility you might just shrug off is life altering to these people.