The FBI and local police are investigating how at least 19 dead Virginians were recently re-registered to vote in this critical swing state.

One case came to light after relatives of a deceased man received a note congratulating him for registering, Rockingham County Commonwealth’s Attorney Marsha Garst said Thursday.

“His family members were very distraught,” said Garst, who confirmed the existence of the FBI and police investigation but said she could provide few details because the case is ongoing.

All 19 were initially registered as voters in the Shenandoah Valley city of Harrisonburg, although a clerk double-checking the entries later raised questions about one. She recognized the name of Richard Allen Claybrook Sr., who died in 2014 at age 87, because his son is a well-known local judge. She happened to recall that the judge’s father had died.