Here is what we know about Celik so far.
Su-24 downing
Celik served as the second-in-command of the Turkmen Coastal Division at the time of the Su-24 incident. He initially claimed that his rebel group had killed both Su-24 pilot Oleg Peshkov and copilot Konstantin Murahtin while the Russian servicemen were parachuting to the ground.
Last week, following his arrest, Celik confirmed that he killed Peshkov, but refused to provide additional information, the Turkish Dogan News Agency reported.
Syria
The Turkmen Coastal Division, also known as the Second Coastal Division, is said to have been established in early 2015. Turkmen rebels have reportedly worked with other militants, including al-Nusra Front and Ahrar al-Sham.
Arrest
The date of the trial has not been set yet.
Background
Celik is said to be the son of a Turkish politician, who served as the mayor of Keban, a small town in the province of Elazig. He is a member of the Grey Wolves, a Turkish youth organization often described as ultranationalist or neo-fascist. The group, particularly active in the 1970s and the 1980s, is said to have killed hundreds of people in Turkey.
The Grey Wolves are affiliated with the far-right Nationalist Movement Party (MHP), the fourth largest party in Turkey.