While I can have no idea what you would deem to be strong evidence, swift Googling can point you to published research from sociologists, et al, about bias and

While I can have no idea what you would deem to be strong evidence, swift Googling can point you to published research from sociologists, et al, about bias and other behaviors that make the justice system dramatically less impartial than it's intended to be. Recent WaPo story, for example: https://www.washingtonpost.com/news/wonk/wp/2016/02/24/researchers-have-discovered-a-surprising-racial-bias-in-the-criminal-justice-system/ https://www.washingtonpost.com/news/wonk/wp/2016/02/24/resea...