I think my concern would be that if it's a first offence, there's no history identified. Quite often, police will have history in their data banks, and not necessarily were there criminal charges laid.
My view would be that if there is a history in addition to a charge, or no history but two or more charges, it should be a reverse onus. It's where there's some evidence that there's a pattern, that this isn't the first time up at bat for this alleged offender.