Anadolu news agency said the main suspect, Abdulkadir Masharipov, an Uzbek citizen who was caught two weeks after the attack, could face 40 consecutive life sentences if convicted on charges of attempting to overthrow Turkey's constitutional order and killing 39 people.
Turkish media have reported that Masharipov confessed to the shooting and told his interrogators that he had received orders from Raqqa, the de facto capital of the Islamic State group in Syria.
The 90-page indictment charges four other suspects allegedly involved in the planning of the attack, including Masharipov's wife, with the same crimes except the firearms violation.
It is not unusual for Turkish prosecutors to demand multiple life sentences in cases of lethal violence. The other 52 suspects will be tried on charges of attempting to overthrow the constitutional order, carrying a sentence of life in prison, and membership in a terror group, with a sentence of 7.5 to 15 years.
Fifty-one of the 57 suspects are behind bars pending trial.
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