Ten-year-old Zilan Yamankılıç died on 19 June 2017 on the Diyarbakır-Bingöl highway when an armoured police bus carrying special operations police officers hit a passenger minibus which was travelling in the opposite direction. The minibus driver, Remzi Menteşe, and passenger İlhan Ayaş also died in the accident.
According to an expert report obtained by the Diyarbakır Chief Public Prosecutor’s Office, police officer Burhan Kolbaşı, who was driving the armoured vehicle, failed to comply with his obligation to drive at a speed appropriate to the technical characteristics of the vehicle and the road, weather, visibility and traffic conditions. The report assessed Kolbaşı as being primarily and fully at fault for the occurrence of the accident.
On 13 February 2019, the Diyarbakır Chief Public Prosecutor’s Office issued an indictment. Taking into account the traffic accident report, the post-mortem examination and autopsy reports, and the expert report, the indictment stated that Burhan Kolbaşı was primarily at fault for the accident and that the other driver, Remzi Menteşe, bore no fault. Following the acceptance of the indictment, proceedings were initiated against Burhan Kolbaşı before the Diyarbakır 3rd Assize Court.
At the first hearing on 2 May 2019, Burhan Kolbaşı argued that it was not possible for him to drive at high speed because the vehicle he was driving was armoured. Defence counsel argued that the accident resulted from a technical malfunction in the vehicle and that the defendant bore no fault. The lawyer for Zilan Yamankılıç’s father, Mehmet Selim Aslan, stated that the tyres of the armoured vehicle were not suitable for the vehicle’s load and technical characteristics, that a 152-metre braking and tyre mark had been identified in the gendarmerie report, and that the defendant’s speed was around 160–170 km/h. He therefore requested a site inspection involving traffic and mechanical engineers. The court rejected the request for a site inspection on the grounds that nearly two years had passed since the accident. In order to resolve the discrepancies between the expert reports obtained during the investigation and those obtained in the civil courts, the court ordered a new report from a three-member expert panel from Istanbul Technical University.
At the second hearing on 26 September 2019, the court noted that the expert report on fault prepared by members of the academic staff of Istanbul Technical University had been received. The court also ordered the Diyarbakır Special Operations Police Centre to provide certificates showing whether the armoured vehicle involved in the accident met the required standards as manufactured, documents and information concerning its suitability under changing weight conditions, and the make, type and technical specifications of the left front tyre fitted to the vehicle at the time of the accident.
At the hearing on 9 January 2020, the court noted that a response had been received from the Diyarbakır Provincial Police Department concerning the technical specifications of the vehicle and tyres. The court referred the case file back to the expert panel consisting of Prof. Dr. M.A.E., Prof. Dr. A.G.G. and Assistant Professor A.T.Ç., who had previously prepared a report, and requested that the discrepancies between the earlier reports be resolved. At the hearing on 25 March 2020, the court also ordered an additional report from the same expert panel.
At the hearing on 15 September 2020, the awaited expert panel report was received and placed in the case file. The report stated that Burhan Kolbaşı was primarily at fault for the occurrence of the accident. In his prosecutor’s opinion on the merits, the public prosecutor likewise stated, based on the expert examinations, that Kolbaşı was primarily at fault and that the other driver, Remzi Menteşe, bore no fault, and requested that the defendant be convicted of causing the death of multiple persons through negligence.
The Diyarbakır 3rd Assize Court found that the armoured bus was travelling above the maximum speed limit set for buses at the time of the accident and that, as a police officer, the defendant was subject to a heightened duty of care and attention. Finding Burhan Kolbaşı primarily at fault, the court sentenced him to five years’ imprisonment for causing the death of multiple persons through negligence. Applying a discretionary reduction in his favour based on his conduct during the proceedings, the sentence was reduced to four years and two months’ imprisonment. This sentence was subsequently converted into a judicial fine of TRY 45,600, payable in 24 equal installments. The lawyers for the intervening parties and defence counsel filed appeals against the judgment.
On 7 February 2022, the 10th Criminal Chamber of the Diyarbakır Regional Court of Appeal overturned the judgment. The Chamber noted that Burhan Kolbaşı was a police officer and that the accident occurred while he was on duty transporting special operations personnel. It therefore held that, under Law No. 4483, permission to investigate had to be obtained from the relevant authority. The Chamber found it unlawful to issue a judgment without first requesting permission to investigate and suspending the proceedings pending the outcome of that process.
Following the reversal, on 28 February 2022, the Diyarbakır 3rd Assize Court assigned a new case number to the file and requested permission to investigate Burhan Kolbaşı from the Diyarbakır Governor’s Office. On 20 May 2022, the Diyarbakır Governor’s Office decided not to grant permission to investigate on the grounds that the defendant bore no fault for the incident.
At the hearing on 14 September 2022, the court was informed that the Governor’s Office had refused to grant permission to investigate. The complainants’ lawyers stated that they had challenged this decision before the Gaziantep Regional Administrative Court and requested that the outcome be awaited. The court decided to await the outcome of the objection. On 8 November 2022, as the Gaziantep Regional Administrative Court had not yet issued a decision, the court ordered that the proceedings be stayed.
After the 6th Administrative Litigation Chamber of the Gaziantep Regional Administrative Court dismissed the objection against the refusal to grant permission to investigate, the case resumed. At the hearing on 7 November 2023, the Diyarbakır 3rd Assize Court stated that the permission required at the investigation stage had been sought during the trial but that the competent authorities had refused to grant permission to investigate and that this decision had become final. The court therefore ordered that the proceedings against Burhan Kolbaşı be discontinued.
Following an appeal by the intervening parties and their lawyers, the 10th Criminal Chamber of the Diyarbakır Regional Court of Appeal overturned the decision to discontinue the proceedings on 24 October 2024. The Chamber found it unlawful to discontinue the proceedings without investigating whether the Diyarbakır Governor’s Office’s decision refusing permission to investigate had been duly served on the persons entitled to challenge it and whether the decision had become final.
Following the reversal, the proceedings resumed. The court requested the file concerning the Diyarbakır Governor’s Office’s decision on permission to investigate, as well as the file in which the objection to the refusal to grant permission to investigate was considered by the Gaziantep Regional Administrative Court. The court also asked the Gaziantep Regional Administrative Court whether there was any other case concerning the defendant.
At the final hearing on 16 October 2025, the Diyarbakır 3rd Assize Court did not conduct a separate assessment of the issue of service identified in the Regional Court of Appeal’s reversal decision. Instead, it accepted that the decision refusing permission to investigate had become final due to the expiry of the statutory time limit and again ordered that the proceedings against Burhan Kolbaşı be discontinued.