On the 22nd April 1993, Stephen Lawrence was murdered in south London. Stephen was black and his attackers were white. The killing and subsequent investigation exposed violent racism on Britain's streets and institutional racism within the British police force. Thanks in large part to the tireless campaign of Stephen's mother, Doreen Lawrence, two of her son's killers were brought to justice in 2012. Laws have been passed and institutions reformed to combat racism but, two decades on, how much has really changed?