Man convicted of murder of teenage actor who starred in new ` `` Harry Potter '' film . Knox , 18 , had rushed out of the bar after he heard that Bishop had threatened his younger brother Jamie Rob Knox , 22 , attacked Rob Knox with 10 knives in southeast London 22 . Knife crime in London is political hot topic due to spate of recent killings .
Man convicted of murder of teenage actor who starred in new ` `` Harry Potter '' film . Rob Knox , 22 , attacked Rob Knox with 10 knives in southeast London 22 . Knife crime in London is political hot topic due to spate of recent killings .