The four board members approved Deters' candidacy after dismissing a protest from a Cincinnati activist who had challenged his residency in Hamilton County.

Kabaka Oba claimed that Deters' move from Liberty Township to Blue Ash on the day he filed as a write-in candidate was "a political trick" and not a legitimate change of address.

"It was a split-second move and it does not meet the residency requirement," Oba said. "Just moving in overnight doesn't make it a residence."

But Oba presented no proof that Deters, a Republican, had not really moved his wife and four children to Blue Ash. And the board members, two Republicans and two Democrats, dismissed the protest for lack of evidence.

Deters' lawyers presented paperwork showing he had properly registered as a voter and as a write-in candidate on Sept. 13, the filing deadline. They also gave the board a sworn statement from Deters affirming that he had moved to a rented home in Blue Ash.

"Believe me, I'd love to be able to sit here today and say Joe Deters isn't qualified to run for office," said Tim Burke, a board member and the county's Democratic Party chairman. "But based on the evidence before us, I can only conclude he is a qualified write-in candidate."

Deters, who was prosecutor for six years in the 1990s, joins two other Republicans and Democrat Fanon Rucker as write-in candidates vying to replace Prosecutor Mike Allen, who withdrew his name from the ballot because of a sex scandal.

GOP officials said they expect the other two Republicans, Melissa Powers and James Rueger, to endorse Deters, although they may remain as registered candidates.