The anti-fascist Ukrainian activist Alexander Kolchenko shared the defendant's bench with the film director. He is accused of assisting Sentsov and an arson attack against the office of the United Russia party.
Sentsov's supporters say he is being held as a political prisoner for his pro-Ukrainian views.
Both detainees have consistently pleaded not guilty.
Ealier, Sentsov claimed he had been tortured while in detention, and said his case was politically motivated.
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