More young people live in urban areas which provide them with more opportunities to commit crimes.
The Home Office is the leading of government department for anything to do with crime - it has 4 priorities:
get rid of/reduce crime
reduce immigration
prevent terrorism
promote growth by keeping the UK safe
In Scotland they have banned sending young offenders to prison and are now in more child-friendly places, this is because of the amount of suicides of young people while in prison.