A Turkish prosecutor has demanded life imprisonment for Andrew Brunson, the North Carolina pastor who was detained in October 2016 for his alleged involvement in a failed attempt to overthrow the Turkish government that year.

The prosecutor in the province of Izmir, where Brunson is being held, charged the 50-year-old with being “a member and executive of the terrorist group” accused of being behind the coup attempt. The Turkish government holds Fethullah Gulen, a Sunni cleric who lives in self-imposed exile in Pennsylvania, responsible for the coup and is demanding his extradition.

But the United States has refused to hand over the septuagenarian imam on the grounds that Turkey has not provided sufficient evidence to prove its claims against him. Brunson’s detention raised questions about whether Turkey is using him as a bargaining chip to get Gulen.

Turkish President Recep Tayyip Erdogan reinforced those suspicions in a speech to police academy graduates last year. “'Give us the pastor back,’ they say. You have one pastor as well. Give him [Gulen] back to us. Then we will try him [Brunson] and give him to you."