Such restrictions on double jeopardy would not be effective in practice, for they attempt to put a value on the relative importance of crimes without using either the prospect of re-offending or the impact on victims. As QC Geoffrey Robertson noted in response to the Law Commission's finding, it is irrational to confine the possibility of re-trials to 'serious crimes' alone and exclude "repetitive, professional" crime like armed robbery. If the intention of the repeal is to bring both offenders to justice and prevent further crime, it is exactly the 'repetitive, professional' criminals who should be targeted.