Wisconsin

Or - failure to change registration? Because you can't just show up at any old polling station .....

Edit: correction - this woman apparently had dual addresses - and whether or not she was legitimately confused about the status of her 'primary' abode - is a matter of conjecture. Apparently the city and prosecutors did not think so. Legally, her primary abode was clearly elsewhere - and not within the city limits. If she didn't legitimately know the legal ramifications ... An unfortunate error by - what we must assume a fairly educated individual.

Also never change address on her driver's license.