Layla Hayoukane, 27, who works in a mobile phone shop near where the stabbing took place, said: "There was an old lady going mad outside. She must have seen what happened because she was going crazy. That's the only reason we knew something had happened." She added: "I thought I saw someone who may have been involved. Two guys walked past our shop and I though they looked suspicious then a couple of minutes later one of them ran back the other way without the other."