The Public Integrity Division opened the case after receiving a complaint that alleged hundreds of people voted illegally, said Deputy District Attorney Dave Demerjian, the head of the division.

Veneziano said his 87-year- old father-in-law showed up to vote at the polls, but couldn’t because someone had requested a vote-by-mail ballot for him.

“He had never voted by mail before,” Veneziano said. “He didn’t know he ordered any ballot. Somebody ordered for him.”