Ren Mekkar was a Cardassian gul in the 24th century.
During the Occupation of Bajor, Gul Mekkar was referred to by the Bajorans as the "Butcher of Belmast". A case of mistaken identity in 2372 saw Rel Mekkar be put on trial instead, but Julian Bashir was able to prove the two men were different people by having Ren Mekkar address the court via subspace transmission. Rel Mekkar was found innocent. (DS9 novel: The Heart of the Warrior)