27.04.2026 10:01
In the Gülistan Doku investigation, Yılmaz Delen, who was the Tunceli Police Chief at the time and currently serves as the Yalova Police Chief, was summoned to give a statement. It was learned that Delen, upon the summons, testified as a witness before the Erzurum Chief Public Prosecutor's Office.
The case regarding Gülistan Doku, a university student who went missing in Tunceli, has been reopened after 6 years. Within the scope of the investigation, 12 people, including the then-governor Tuncay Sonel, his son Mustafa Türkay Sonel, and the then-chief physician of Tunceli State Hospital, Çağdaş Özdemir, were arrested.
YALOVA POLICE CHIEF SUMMONED FOR TESTIMONY
A new development has occurred in the case that has long been on Turkey's agenda. Yılmaz Delen, who served as the Tunceli Provincial Police Chief at the time of the incident and currently serves as the Yalova Provincial Police Chief, was summoned to Erzurum to give a statement. Delen, whose testimony is being sought as a witness, has had his statement proceedings initiated.
BEING INTERVIEWED AS A WITNESS
It was stated that Yılmaz Delen will be heard as a witness for now within the scope of the investigation. Delen, who is not in the position of a suspect, is considered likely to provide information regarding the initial stages of the incident, which could clarify the long-debated allegations of negligence.
On the other hand, it is claimed that the Erzurum Chief Public Prosecutor's Office may make new evaluations based on the findings obtained during the statement process, and if a determination of negligence is made, Delen could be included in the case as a suspect.
WHAT HAD HAPPENED?
The High Council of Judges and Prosecutors (HSK), with its June 2024 decree, appointed Ebru Cansu—one of Turkey’s three female chief prosecutors—to Tunceli. As soon as she started her duty, she took down the Gülistan Doku case file and began examining it.
Upon the instruction of Chief Prosecutor Ebru Cansu, who re-examined the investigation from scratch, a special team was formed consisting of personnel from the Gendarmerie Crime Investigation Teams (JASAT), known as "Gendarmerie Detectives." All city KGYS footage and PTS records from the day before and the day Gülistan Doku disappeared were collected.
New footage of Gülistan was also found; a total of 70 KGYS recordings, 67 of which were on main arteries, along with an additional 700 hours of security camera footage, were added to the case file. The footage, which revealed where Gülistan came from before going to the cafe to meet her boyfriend Zeinal Abarakov, and when she left the cafe to go to her teacher, was watched second by second by the Chief Public Prosecutor's Office and the special team, investigating Gülistan's fate.
Additionally, some suspects were added to the file, and HTS and PTS studies were conducted. After the necessary work was completed, operations were launched. In the case, which turned from a missing person file into a "murder" investigation, operations were carried out on April 14, 17, and 24 on suspicion of murder. 17 suspects were detained. A red notice was issued for Umut Altaş, who is a suspect in the file and is located in the USA.
12 SUSPECTS ARRESTED, INCLUDING THE THEN-GOVERNOR AND HIS SON
After their processing at the gendarmerie, among the suspects sent to the courthouse, Tuncay Sonel's son Mustafa Türkay Sonel, and Erdoğan Elaldı—who was determined through cell site analysis to have had the last contact with Gülistan Doku and was a Special Provincial Administration employee at the time—were arrested on charges of "Intentional killing."
Gülistan Doku's ex-boyfriend Zeinal Abarakov, Abarakov's father Engin Yücer and mother Cemile Yücer, fugitive suspect Umut Altaş's father Celal Altaş and mother Nurşen Arıkan, dismissed police officer Gökhan Ertok, and Şükrü Eroğlu, who was Tuncay Sonel's close bodyguard at the time, were arrested on charges of "Concealing and destroying crime evidence."
Ferhat Güven was arrested and sent to prison on charges of "Robbery" due to his action against Gülistan Doku's sister, Aygül Doku. The then-chief physician of Tunceli State Hospital, Çağdaş Özdemir, who was detained in Bursa on allegations of deleting Gülistan Doku's hospital records and brought to the Tunceli Courthouse, was also arrested on charges of "Falsifying, destroying, or concealing official documents."
Tuncay Sonel was arrested on charges of "Destroying, concealing, or altering crime evidence," "Obstructing, corrupting, destroying, or altering data in an information system, unlawfully giving or seizing personal data," and "Falsifying, destroying, or concealing official documents." Suspects U.A., along with S.G. and S.Ö., who were responsible for cameras at Munzur University, were released under judicial control.
On the evening of April 24, Tunceli State Hospital IT staff members Burçin Y. and Yücel E. were detained on suspicion of deleting hospital records, under the accusation of "Destroying and concealing evidence." The suspects' statement proceedings at the gendarmerie continue.