Ms Robertson, who said she was not related to Matthew but had been his best friend for four years, appealed for young people to stay calm and call a halt to the violence.
"If they [the young people] want to keep rioting they know they’ll get taken, they’ll get caught,” she said. “They’re going to be locked up and they won’t be at his funeral."
"He was my best friend,” she said, adding that she met him through her cousin, who had been going out with him. "I saw him in every jail he went to."
