The young couple were found shot to death in their car 10 days after they married against the wishes of the bride's family, Today's Zaman reported.
Sonay Ogmen, 26, and Zekeriya Vural, 29, each died from a single bullet to the forehead.
Police determined the couple had been killed by someone they knew sitting in the back seat of their car.
"I shot both of them," the bride's brother, Gonay Ogmen, told police after he was arrested. "We didn't want that groom."
The groom's uncle, Cemal Vural, said the bride's family opposed the marriage because she was Christian and Zekeriya Vural was Muslim.