Then it should be easy to take a sampling of precincts suspected of vote fraud and simply call the people who voted in a follow up poll. Ask them if they voted and for whom?
Also the voter lists should be seeded with fake names by the FBI. The FBI could look into fraud when their 'fake' people vote. When nonexistent people vote, it's a sure sign of fraud.
I'm amazed people object to ‘the dead’ voting... that's one of the ways to spot fraud. Democrats don't set out to vote the dead - they'd be thrilled if we'd clean that group off the voter roles. When dems cheat they VOTE THE PEOPLE WHO DON'T BOTHER TO VOTE. The dead vote is an accidental byproduct of that type of fraud.