It was public outrage over the murder of black teenager Stephen Lawrence and the ensuing removal of a longstanding legal principle that made the prosecution of Gary Dobson and David Norris possible. Lawrence, an 18-year-old sixth form student from Eltham, South London, was stabbed to death on the night of April 22, 1993, by a gang of white youths.
 
It was an unprovoked attack that saw him killed …