Gencer's Instagram account showed that he was in Manbij last year. While he is seen with a weapon in this picture, he posted others from the southeastern province of Antep upon his return to Turkey with the caption, "Back from the duty."

He also shared multiple pictures of himself at a shooting range in İzmir on his Instagram, which is filled with messages of "revenge." 

Gencer on June 17 attacked the HDP building in İzmir's Konak district and killed 20-year-old Deniz Poyraz. He was detained shortly after.

Turkish authorities said that Gencer was a healthcare employee in the past.