Turkish police have arrested a teenager in the northern town of Trabzon as the suspected killer of a Catholic priest.
Father Andrea Santoro, an Italian, was shot dead in his church on Sunday.
Turkish politicians have condemned the killing and say they hope there is no link to the widespread outrage over cartoons of the Prophet Muhammad.
After a major manhunt, police detained a 16-year-old high school student early on Tuesday morning. A gun was seized at the house they raided.
The gun has been sent away for ballistic tests to determine if it is linked to the murder.
Father Andrea Santoro was shot in the chest on Sunday. Witnesses say the gunman shouted "God is great" as he fled.
Police say they still have no clue what motivated the killing, the BBC's Sarah Rainsford reports from Istanbul.
There has been widespread speculation that the murder may have been an act of revenge linked to growing protests around the world by Muslims angry about cartoons satirising the Prophet Muhammad which appeared in the European press.
Turkey's Prime Minister Recep Tayyip Erdogan has said he hopes there is no link. He has expressed his deep regret for the murder.
The priest's work with prostitutes in the area has also been suggested as a possible motive for the attack.