The recent killing of London schoolgirl Elianne Andam, who died after being stabbed on a Croydon street while on her way to school, has once again prompted lengthy debate around knife crime; former police officer Oliver Laurence, who grew up in Croydon, shares his thoughts on what can be done to tackle the crisis – including listening to the views of those with first-hand experience of knife crime in their community, such as AJ Wright.