What Biometric Technology Does and Doesn’t Add to Voting is the title I see.

Be it said that in well-run countries voter fraud is so infrequent that neither voting machines nor "Biometric Voting Technology" are needed. Just use pen and paper and do a reasonable check on voter identity, like looking at their ID cards before voting. There is absolutely no need to go beyond this. With paper-based voting each vote produces a paper trail that is also the original voting document, a.k.a. the Source of Truth that answers the question "who did this anonymous person vote for?". When you do it with voting machines then either you have to use them to punch holes or make other marks on paper or cardboard, with which I'm by and large fine if nothing else is done. If a voting machine has counters or does data transmission in addition to marking a paper slip, things get much ickier: now you have several sources of truth and have to decide what to do if the counter or the manual recount is correct. Voting machines that work by only storing votes electronically are a complete disaster and should never be used.