“If you are old enough to commit these crimes, you are old enough to face the punishment.”
Don’t you see David? Punishment doesn’t rhyme with crime. And shouldn’t it be ‘do the crime’?
How about, “If you’re old enough to do the establishment, you’re old enough to do the punishment”? Perhaps not snappy enough.
“If you’re going to run amok, you’re going to come unstuck”? That doesn’t come across as being especially tough does it.
Let’s try the honest approach for a change: “If you’re old enough to commit these crimes, you’re old enough to face a community service order.”
UPDATE: As confirmed by The Magistrate’s Blog