Turkish police say they apprehended Sagin Sogut, allegedly part of the plot to kill Karlov, thanks to CCTV camera footage, according to Turkey's Anadolu news agency.
According to Anadolu, Sogut, who is believed to be a high-ranking member of what Turkey calls the FETO terrorist organization, fled immediately after the assassination. On February 26, he visited a bank in Ankara. The CCTV footage reportedly shows Sogut approaching the bank, making a phone call and entering the building. Security personnel noticed Sogut's worried appearance, as he constantly looked at the cameras, the report says.
During the subsequent investigation, the Ankara police department's anti-terror division studied the camera footage on the order of the Turkish Prosecutor's Office, and managed to trace Sogut via various cameras located on the streets of Ankara. Sogut was eventually apprehended on April 5, 2018.
The Prosecutor's Office believes that it was Sogut's influence that shaped Altintas's radical views. They reportedly think Sogut ordered Altintas to kill Karlov, planned the entire operation and then erased Altintas' emails.
A total of seven people have been arrested in connection with the assassination, including three former police officers. The Turkish authorities blame the Gulenist Movement, which it denotes as "FETO" (the Turkish abbreviation for Gülenist Terror Organisation), led by cleric Fethullah Gulen, for the assassination. Gulen denies all allegations.