"Personal codes never seem to line up with the judicial system, do they?" he asks. There's no judgement at all in his tone, because his own personal set of morals certainly don't fall in line with how he's meant to do his job as a detective. The law is restrictive and it gives too many rights to criminals. John understands the importance of innocence until proven guilty, but he's also seen too many extremely guilty people get off on technicalities.

So he tries to make sure that doesn't happen in Darrow. Even if he has to go above, beyond or below the law to do so.