Fifteen-year-old Alexis Grigoropoulos was shot dead in central Athens on December 6. The killing triggered mass protests and a wave of clashes between youths and police.
Epaminondas Korkoneas, 37, was charged on December 7 with murder and illegal use of his weapon. His lawyers said on Wednesday that ballistics results had established that Korkoneas acted in self defense, and that the boy was killed in a bullet ricochet.
Eyewitnesses said the officer took aim at the victim and killed him in a direct hit.
The second officer, Vassilios Saraliotis, 31, was charged with abetting his partner. Both have been held in custody since Sunday.
Riots over the boy's death led to broader protests against the ruling conservative party's economic and social policies. Athens has entered a sixth day of skirmishes, with masked youths throwing stones and Molotov cocktails at police.
