We should trust but verify the results. The basis of facts should be settled in the following:
1. Select all ballots that were sent to the same address - or sent to the same Post Office (grouping all PO Boxes by post office).
^ Here you are trying to see if there is systemic voting behaviors out of the ordinary -- i.e. did 10+ ballots go to one address.
2. Select all ballots that were sent to an alternate address than the voter registration.
^ This is a general query -- select a sample set of these and confirm with the registered voter that they did indeed receive a mail in ballot.
3. If above is inconclusive, select all registered voters that requested a mail in ballot against the 2017-2018 Equifax Data to determine if correlations occur.
4. Select all ballots that were the voter did not vote in the last X elections (there are political consultancies that provide information on who NOT to waste your time on because they do not vote), did these people request a mail in ballot? Were these ballots sent to an alternate address?
For clarification [1], if one were armed with a SSN or DL and a previous address, one could request a ballot on behalf of another person AND have that ballot redirected to a location of their choosing... including a PO Box. The form is included here for reference.
[1] https://www.votespa.com/Register-to-Vote/Documents/PADOS_Mai...
EDIT: just so you know, I think both of them did things like this. I want my d%mn democracy back.