The investigation into the disappearance of university student Gülistan Doku has taken a major turn after a technical signal from Ankara changed the course of the case, according to Tunceli Chief Public Prosecutor Ebru Cansu.
Speaking about the ongoing investigation to Sabah newspaper, Cansu said the case file has grown from seven folders to 14 folders as a result of renewed examinations carried out under strict confidentiality. She noted that a restriction order was applied from the beginning to prevent access by unauthorized persons, including courthouse staff.
"We ensured that the file could not be seen by unauthorized persons, including court personnel,” she said, adding that the process was managed in a highly controlled and disciplined manner to avoid any information leaks.
Cansu said the most critical turning point came when technical analysis revealed that Gülistan Doku’s phone line sent a signal from a district in Ankara. "This technical data completely changed the course of the investigation,” she said. "The signal revealed interventions on the SIM card and exposed the network connected to the phone line.”
She explained that this finding shifted the direction of the investigation and led to deeper analysis of digital data, eventually bringing attention to an individual named Gökhan Ertok.
Originally considered a possible suicide case, the file has now developed into a broader criminal investigation based on evidence including witness statements, digital records, and technical findings.
"In law, we do not act according to the name on the file cover,” Cansu said. "What matters is the direction shown by the evidence.”
She added that the investigation is being carried out with specialized units and advanced technical support, including search operations across rural and mountainous areas of Tunceli using forensic equipment and Gendarmerie Crime Investigation Teams (JASAT) teams.
The probe has also revealed inconsistencies in official records. While police system data showed a hospital entry for Doku, no corresponding hospital medical file was found, prompting further examination by the Ministry of Health.
Gülistan Doku, a university student in Tunceli, eastern Türkiye, has been the subject of an ongoing investigation since January 2020 after she was reported missing. While the case was initially treated as a disappearance, later investigative findings led authorities to expand the scope into a potential homicide investigation.