Police are facing questions over why the killer of 12-year-old Leo Ross was left free to stab him at random, after months of rampaging around his neighbourhood. Her teenage assailant beat her with her own walking stick, inflicting serious injuries, before pushing her into the river. A single stab wound, with no further injuries found on either Leo or his attacker - suggesting a quick, ruthless assault. Following the verdicts,Leo's heartbroken birth mother Rachel Fisher said: 'My son Leo was the sweetest, most kind-hearted boy. Leo's foster family, the Westons, added: 'Not a day goes by where we don't think about Leo.