now on bbc news it's hardtalk. welcome to hardtalk. i'm stephen sackur. black and white americans have always had vastly different experiences within their country's justice system. you see it in so many different data sets, from police violence to incarceration to sentencing. it's impossible to understand without reference to america's history of institutionalised racism. understanding it is one thing, the real challenge is how to change it. my guest is bryan stevenson, civil rights lawyer and founder of the equaljustice initiative. will equality ever be more than a dream?