After the attack, the police force referred itself to the Independent Office for Police Conduct (IOPC) because of its contact with him
The mandatory referral was looked into by the IOPC which concluded on Friday no further investigation was required into the force’s conduct.
It added that the “matter should be returned to the force to handle as it deems appropriate”.
It said: “We have reminded the force of its obligations, and that if evidence were to come to light that anyone serving with the police may have breached standards of professional behavior or committed a criminal offense in connection with this, they should refer relevant matters that us.”
Epsom College, which offered its condolences and sympathies to the family, is working alongside the police as part of the investigation.
The school added: “We must now focus on the welfare and wellbeing of our pupils and staff, and work to ensure that they receive all the comfort, warmth and support required from the Epsom College community.”
It has refused to offer any further statements about the situation.