Comment by AngryData
The same "alternative" that there is to every other crime in existence, proving the person you charged with a crime actually committed the crime. The default is suppose to be innocence, not guilty. It is the state's responsibility or problem to prove someone is guilty beyond a reasonable doubt, not a citizen's responsibility to prove their continued innocence at all times.
I mean, the state obviously has photo evidence. So you need to show that either the photo was taken in error, that it misidentified your vehicle or that you weren't the legal owner at the time.