Turkish criminal procedure is governed by the Code of Criminal Procedure (Ceza Muhakemesi Kanunu, Law No. 5271, CMK), which defines the rights of suspects and accused persons at every stage from police detention through trial and appeal. The CMK establishes the right to silence and the right to defense counsel at the interrogation stage — rights that exist on paper but that are practically meaningful only when a defense lawyer is present to invoke and enforce them in real time. A suspect who is questioned by police without counsel, who waives the right to silence without understanding its implications, or who makes statements that are later used as the primary evidence in a prosecution has limited ability to undo those consequences after the fact. The Turkish Penal Code (Türk Ceza Kanunu, Law No. 5237, TCK) defines the offenses and penalties, while the CMK defines how those offenses are investigated and prosecuted — and the CMK's procedural framework creates specific defense opportunities at each stage that are available only if counsel is engaged early enough to use them. The CMK is accessible at Mevzuat. This page sets out how we approach criminal defense work in Turkey across the main stages and case categories.
Police detention and pre-indictment defense
A lawyer in Turkey advising on police detention rights must explain that under CMK Article 147, a detained suspect has the right to remain silent, the right to defense counsel from the moment of detention, and the right to have counsel present during any police interrogation. These rights cannot be waived on the suspect's behalf by a third party and must be actively communicated to the suspect by the detaining authority before any interrogation begins. A police interrogation conducted without the suspect being informed of their right to silence, or conducted without the suspect's counsel being given a reasonable opportunity to be present, produces a procedurally irregular statement that a defense lawyer can challenge as evidence before the court. In our practice, the first priority when a client contacts us from custody is to attend the interrogation facility, review the file that has been made available to the defense at that stage, advise the client on whether and to what extent to respond to questions, and challenge any procedural irregularities in the detention. Practice may vary by authority and year — verify current CMK provisions and Turkish court interpretations of statement admissibility requirements before advising any detained client on their procedural rights.
An Istanbul Law Firm advising on the detention duration limits under Turkish law must explain that CMK Article 91 sets the maximum permissible detention period before the suspect must be either released or brought before a judge: 24 hours for ordinary offenses (extendable by the prosecutor by a further 24 hours in defined circumstances), and extended periods under the Anti-Terror Law (TMK) for terrorism-related offenses. Once the detention period expires without a judicial remand (tutukluluk) order, the suspect must be released. A judicial remand requires a judge to find specific grounds — the existence of reasonable suspicion of the offense and either a flight risk or a risk of evidence tampering — and a defense lawyer can oppose the remand application by challenging the adequacy of the suspicion and contesting each stated ground. Where remand is ordered despite the defense's opposition, an immediate appeal to the criminal court of peace (sulh ceza hâkimliği) is available under CMK Article 268. Practice may vary — verify current Turkish court practice on remand application procedure and the specific grounds most successfully used in opposition arguments for the offense category at issue.
Investigation stage: file access and evidence challenges
A law firm in Istanbul advising on defense rights during the investigation stage must explain that Turkish criminal procedure distinguishes between the investigation phase (soruşturma), which is conducted by the public prosecutor with police assistance, and the prosecution phase (kovuşturma), which begins when an indictment is filed and a trial court is assigned. During the investigation phase, defense counsel's access to the investigation file is governed by CMK Article 153, which gives the suspect's lawyer the right to examine the file and obtain copies of documents — except for documents that the prosecutor has specifically restricted on the ground that disclosure would endanger the investigation. Restrictions on file access during the investigation phase can be challenged before the criminal court of peace. A defense lawyer who systematically reviews the investigation file as it develops — tracking what evidence the prosecution has collected, identifying gaps in the chain of custody, and preserving objections to procedurally irregular evidence collection — is in a substantially stronger position at trial than one who reviews the file only after indictment. Practice may vary by authority and year — verify current CMK file access provisions and Turkish court practice on investigation-stage file restriction challenges before advising clients on their rights at this stage.
An English speaking lawyer in Turkey advising on evidence suppression opportunities in Turkish criminal procedure must explain that Turkish courts apply an exclusionary rule (delil yasakları) under CMK Articles 206–217 that prohibits the use of evidence obtained through means that violate fundamental rights or that was collected through an illegal search, seizure, or wiretap. Evidence obtained without a valid judicial warrant, evidence obtained through prohibited interrogation techniques, and digital evidence collected without proper chain of custody documentation are all potentially subject to exclusion. The challenge to illegally obtained evidence must typically be raised before or at trial — a defense lawyer who identifies the specific basis for exclusion and files a timely challenge can remove the problematic evidence from the prosecution's case before it influences the court. We review the investigation file specifically for chain of custody failures, warrant validity issues, and interrogation procedure compliance as a standard step in every criminal defense mandate. Practice may vary — verify current Turkish criminal court evidentiary exclusion standards and the procedural deadline for raising exclusion objections before finalizing the defense strategy for a specific case.
Trial defense and courtroom strategy
A Turkish Law Firm advising on trial defense strategy must explain that a Turkish criminal trial (duruşma) is an adversarial proceeding before a single judge or a panel of judges in which the prosecution presents evidence and the defense challenges it, presents counter-evidence, and argues for acquittal or a lesser charge. The defense's most important tools at trial are: cross-examination of prosecution witnesses, which can expose inconsistencies and credibility weaknesses in the prosecution's case; the presentation of defense witnesses and expert opinion, including counter-expert reports that challenge the methodology of prosecution-appointed experts; procedural objections to the admission of specific evidence; legal submissions challenging the adequacy of the prosecution's evidence to sustain the charged offense; and — where the facts are largely not in dispute — mitigation arguments that affect the court's sentencing discretion. Turkish penal courts have formal discretion in sentencing within the TCK's defined ranges, and effective mitigation presentation can make the difference between a suspended sentence and a custodial sentence in many offense categories. Practice may vary by authority and year — verify current Turkish criminal court procedural rules for defense submissions, expert evidence, and witness examination before finalizing trial preparation.
A lawyer in Turkey advising on the CMK Article 253 simplified procedure (basit yargılama usulü and uzlaştırma) must explain that Turkish criminal procedure provides two mechanisms that can resolve certain cases without a full trial. Uzlaştırma (mediation/conciliation) is available for a defined list of offenses — primarily offenses against individuals rather than against the public — and allows the prosecutor to refer the case to a court-appointed mediator who facilitates an agreement between the suspect and the victim. If an agreement is reached, the prosecution is discontinued. A separate mechanism — the simplified procedure under CMK Article 251 — allows certain less serious cases to be resolved through a written process without a full hearing, producing a reduced sentence. Both mechanisms must be assessed on a case-by-case basis for eligibility and strategic suitability. Not every case that is technically eligible for these procedures is better resolved through them — sometimes a contested trial produces a better outcome. Practice may vary — verify current Turkish court practice on uzlaştırma eligibility and simplified procedure applicability for the specific offense category before advising a client on the options.
White-collar and financial crime defense
An Istanbul Law Firm advising on white-collar criminal defense must explain that financial and economic crime cases in Turkey — fraud (dolandırıcılık, TCK Article 157), embezzlement (zimmet, Article 247), misuse of trust (güveni kötüye kullanma, Article 155), money laundering (suç gelirlerinin aklanması, Article 282), and bribery (rüşvet, Article 252) — present specific defense challenges because the prosecution's evidence is typically documentary and financial, requiring the defense to engage with complex accounting records, transaction trails, and regulatory documentation. Defense in financial crime cases requires an early forensic accounting review that identifies the alternative explanations for the financial patterns the prosecution characterizes as criminal, the specific intent (kast) elements the prosecution must prove and how they intend to prove them, and any procedural irregularities in the collection of financial evidence including banking and tax records. We work with forensic accountants and financial experts as a standard component of white-collar defense mandates. Practice may vary by authority and year — verify current Turkish criminal court standards for financial expert evidence admissibility and the prosecution's disclosure obligations in financial crime cases before finalizing the defense strategy.
A Turkish Law Firm advising on corporate criminal liability in Turkey must explain that while Turkish criminal law does not apply criminal liability directly to legal entities — companies cannot be convicted of crimes under the TCK — corporate officers, directors, and managers can be personally prosecuted for offenses committed within the scope of their corporate roles. This means that a company's compliance failure can trigger personal criminal liability for the individuals who were responsible for the compliance function, and an internal investigation that identifies compliance gaps can become a roadmap for the prosecution if it is produced without privilege protections. We advise companies on the privilege implications of internal investigations, the appropriate scope of voluntary disclosure to regulatory authorities, and the defense strategy for individuals facing prosecution arising from corporate conduct. The commercial litigation Turkey framework — covering corporate liability and regulatory enforcement — is analyzed in the resource on commercial litigation Turkey. Practice may vary — verify current Turkish prosecutor and court approaches to corporate-related personal criminal liability for officers and directors before advising on any corporate compliance or disclosure decision.
Cybercrime and digital evidence defense
A law firm in Istanbul advising on cybercrime defense must explain that offenses under Turkey's Information Technology Law (Law No. 5651) and the TCK's cybercrime provisions — including unauthorized access to information systems (TCK Article 243), destruction or alteration of data (Article 244), fraud committed through information systems (Article 158), and online defamation — present specific evidentiary challenges because the prosecution's case typically rests on digital evidence: IP logs, device forensics, platform records, and digital transaction data. The evidentiary value of digital evidence in Turkish criminal proceedings depends on the chain of custody from the moment of seizure through the forensic examination and the court presentation — and chain of custody failures, procedural irregularities in the search and seizure of digital devices, and methodology errors in the forensic examination are all grounds for exclusion or weight reduction that a defense lawyer experienced in digital evidence can exploit. We retain specialist digital forensics consultants to conduct independent examination of seized devices and to challenge the prosecution's forensic methodology. The cybercrime defense Turkey framework is analyzed in the resource on cybercrime defense Turkey. Practice may vary by authority and year — verify current Turkish criminal court admissibility standards for digital evidence and the specific procedural requirements for lawful digital device seizure before challenging digital evidence in a pending case.
Foreign nationals and international criminal matters
An English speaking lawyer in Turkey advising on criminal defense for foreign nationals must explain that a foreign national detained in Turkey has the right under CMK Article 147 and international consular convention obligations to be informed of their right to have their consulate notified, to communicate with their consulate, and to receive consular assistance during the proceedings. Turkish law also requires that proceedings affecting a foreign national who does not speak Turkish be conducted with the assistance of an interpreter, and the interpreter's services must be provided without charge to the suspect. A foreign national who was interrogated without an interpreter, or who was not informed of their consular notification rights, has specific procedural grounds for challenging the admissibility of statements made during that interrogation. We coordinate with the client's consulate, manage interpreter arrangements, and ensure that all procedural protections specific to foreign nationals are invoked at every stage of the proceeding. Practice may vary — verify current Turkish practice on consular notification timing and foreign national procedural rights before advising any detained foreign national on their specific entitlements.
A lawyer in Turkey advising on extradition and international criminal cooperation matters must explain that Turkey is a party to the European Convention on Extradition and has bilateral extradition treaties with numerous countries. Where a foreign state requests the extradition of a person present in Turkey, the Turkish Ministry of Justice reviews the request and refers qualifying cases to the competent Turkish court, which assesses the legal conditions for extradition — including dual criminality, the political offense exception, and the prohibition on extradition where there is a risk of persecution based on protected characteristics. Defense in extradition proceedings requires a specific analysis of the applicable treaty, the Turkish statutory extradition framework (Law No. 6706), and the rights of the requested person to challenge the extradition order before the Turkish court. Where Interpol red notices or diffusions have been issued, we advise on notice challenge procedures before the Interpol Commission for the Control of Files (CCF). Practice may vary by authority and year — verify current Turkish extradition law provisions and Turkish court practice on extradition defense grounds before advising on any international criminal cooperation matter.
Appeals and post-conviction remedies
An Istanbul Law Firm advising on criminal appeals in Turkey must explain that Turkish criminal procedure provides for two levels of appeal following a first instance criminal conviction. The first level is the regional appellate court (Bölge Adliye Mahkemesi, BAM), which conducts a full review of both the facts and the law — examining the evidence and the trial court's application of the TCK — and can affirm, modify, or reverse the conviction. The second level is the Court of Cassation (Yargıtay), which reviews questions of law only and cannot re-examine the facts established at trial. Both levels of appeal have strict procedural deadlines — the notice of appeal to the BAM must be filed within seven days of the oral pronouncement of the sentence — and a failure to meet these deadlines may result in the conviction becoming final. Defense counsel who has been present at trial should file a protective notice of appeal immediately after sentencing, even before the reasoned judgment is available, to preserve the deadline. Practice may vary — verify current Turkish criminal appeal procedural deadlines and the required content of the appeal petition for the specific offense category before finalizing the appeal strategy.
A best lawyer in Turkey advising on Constitutional Court individual applications and ECHR petitions in criminal matters must explain that a person who has exhausted all available domestic criminal remedies and who believes their constitutional rights were violated in the criminal proceedings can file an individual application (bireysel başvuru) before the Turkish Constitutional Court within 30 days of the final domestic decision. The Constitutional Court's remedy is typically a declaration of violation and a referral back to the criminal court for a new trial — it does not itself acquit the applicant. For violations of the European Convention on Human Rights that the Constitutional Court has failed to remedy, a petition to the European Court of Human Rights remains available — though ECHR proceedings are lengthy and the primary remedy is a declaration of violation and just satisfaction rather than direct release. We assess the viability of each post-conviction remedy on the specific facts and advise on the realistic timeline and outcome for each path. The Istanbul Bar Association at istanbulbarosu.org.tr provides resources for identifying qualified practitioners. Practice may vary by authority and year — verify current Constitutional Court and ECHR admissibility requirements and processing timelines before advising on post-conviction remedy strategy.
How we work
A law firm in Istanbul accepting a criminal defense mandate begins with an immediate review of the stage the case has reached — because the available defense tools and the urgency of each action depend entirely on where in the CMK process the case sits. A client in police custody requires immediate physical presence at the detention facility and a decision about interrogation strategy within hours. A client who has received a notice to appear as a suspect before the prosecutor requires file access, case analysis, and interrogation preparation within days. A client who has been indicted requires a full defense file review and trial strategy before the first hearing. A client who has been convicted requires a protective notice of appeal within seven days. In every case, the first step is an honest assessment of the evidence, the applicable TCK provision, the realistic range of outcomes, and the specific procedural opportunities available at the current stage. Practice may vary — check current CMK procedural rules and Turkish court practice before acting on any criminal defense strategy, as procedure and judicial interpretation evolve.
ER&GUN&ER handles criminal defense mandates for Turkish nationals and foreign clients across the full range of offense categories — economic and financial crime, cybercrime, corporate compliance-related prosecutions, drug offenses, violence and property crimes, and international criminal cooperation matters including extradition and Interpol proceedings. We work in English throughout all mandates involving foreign clients and coordinate with specialist forensic accountants, digital forensics experts, and foreign co-counsel as required by the specific case. Practice may vary — check current guidance before acting on any information on this page.
Frequently Asked Questions
- What are my rights if I am detained by Turkish police? Under CMK Article 147, you have the right to remain silent, the right to legal counsel from the moment of detention, and the right to have your lawyer present during any interrogation. You must be informed of these rights before any questioning begins.
- How long can Turkish police hold me without bringing me before a judge? For ordinary offenses, the maximum detention period before a judicial remand hearing is 24 hours, extendable by the prosecutor by a further 24 hours in specific circumstances. Extended periods apply for organized crime and terrorism offenses.
- Can I remain silent during police questioning in Turkey? Yes. The right to silence under CMK Article 147 applies throughout the investigation and trial. Exercising the right to silence cannot be used against you as evidence of guilt. We advise each client specifically on when and how to exercise this right.
- As a foreign national, do I have the right to consular assistance? Yes. Turkish law and applicable consular conventions require that you be informed of your right to have your consulate notified, and that you be provided with interpreter assistance if you do not speak Turkish. These protections must be actively invoked.
- Can illegally obtained evidence be excluded in Turkish criminal proceedings? Yes — CMK Articles 206–217 establish a delil yasakları (evidence prohibition) framework. Evidence obtained through illegal search and seizure, without a valid warrant, or through prohibited interrogation techniques can be excluded. The challenge must be raised at the appropriate procedural stage.
- What is the difference between uzlaştırma and a plea deal? Uzlaştırma is a court-supervised conciliation process between the suspect and the victim, available for specific offense categories. If successful, the prosecution is discontinued. It is not a plea deal in the common law sense — it requires the victim's genuine agreement, not merely the prosecutor's consent.
- How long does a Turkish criminal trial take? This depends heavily on the offense category, the complexity of the case, and the court's workload. Simple cases may be resolved in a few hearings over six to twelve months. Complex financial crime or organized crime cases can last two to four years at first instance, with appeal adding further time.
- Can I appeal a Turkish criminal conviction? Yes — first to the regional appellate court (BAM) on both facts and law, then to the Court of Cassation (Yargıtay) on law only. The notice of appeal to the BAM must be filed within seven days of the oral pronouncement of the sentence.
- Can a company be convicted of a crime in Turkey? Turkish criminal law does not impose criminal liability on legal entities. However, the individuals who directed, managed, or were responsible for the conduct giving rise to the offense — directors, managers, compliance officers — can be personally prosecuted.
- Do you represent clients facing extradition to or from Turkey? Yes — we handle both inbound extradition requests (foreign states seeking extradition of persons in Turkey) and outbound matters where Turkish nationals face extradition proceedings abroad. We also advise on Interpol red notice and diffusion challenges before the Interpol CCF.
Author: Mirkan Topcu is an attorney registered with the Istanbul Bar Association (Istanbul 1st Bar), Bar Registration No: 67874. His practice focuses on cross-border and high-stakes matters where evidence discipline, procedural accuracy, and risk control are decisive.
He advises individuals and companies across Criminal Defense Law, Commercial Litigation, International Criminal Cooperation, and cross-border enforcement matters where procedural precision under time pressure is decisive.
Education: Istanbul University Faculty of Law (2018); Galatasaray University, LL.M. (2022). LinkedIn: Profile. Istanbul Bar Association: Official website.
