Just FYI, like most studies of behaviors and their causes in large populations, the hypothesis that lead exposure resulted in more crime is not proven, see e.g.: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5801257/

My priors (from a Bayesian perspective) that lead, which in high doses provably can result in brain damage, can have more subtle effects on behavioral inhibition and executive function is pretty high, but I still do not know that I would feel confident saying the evidence is clear.