When people feel alone and unsupported by their community they are going to take matters into their own hands in the best way they know how. The rioters, the shop keepers, the police, they are likely all acting in a manner that they feel will best protect what is most dear to them.
I don't have a solution but I can't help that think if everyone valued and respected each other as human beings, regardless of race, gender, sexual orientation, or socio-economic class there would be less violence and property damage in Baltimore (and everywhere).