The Crown Prosecution Service (CPS) would apply the two stage test as set out in the Code for Crown Prosecutors. The first stage is the evidential test: there has to be sufficient evidence to provide a realistic prospect of conviction.
If there is, consideration has to be given to the second test, namely, whether a prosecution is required in the public interest. Relevant public interest considerations are set out in the code. A prosecution will be brought if the balance of public interest factors is in favour of a prosecution. If the youth has admitted the offence when interviewed, consideration will be given as to whether the case is suitable for diversion: in such cases, the option would be for the police to administer a reprimand or final warning.