tl;dr version: http://tldr.io/tldrs/50e6993885d8d1617b000a23/americas-real-...

There is now enough statistical proof that lead is the prominent cause of crime. Crime rates and lead concentrations are extremely well correlated everywhere: the more lead in the environment, the more crimes will occur. Furthermore, it is scientifically proven that lead has a very negative impact on the brain, killing gray matter and impairing neuronal communication. Unfortunately, this theory hasn't been taken seriously by the government yet because it doesn't serve any political agenda.