Turkish Criminal Procedure Explained

Criminal procedure in Türkiye is governed by the Code of Criminal Procedure (Ceza Muhakemesi Kanunu) No. 5271, adopted on 4 December 2004 and published in the Resmî Gazete of 17 December 2004 (No. 25673). It divides every case into two phases. The soruşturma (investigation) runs from the moment the competent authorities learn of a suspicion that an offence has been committed until the indictment is accepted; the kovuşturma (prosecution, in practice the trial) begins with that acceptance and continues until the judgment becomes final (CMK Art. 2). The investigation belongs to the public prosecutor, the trial belongs to the court, and the same person is called a şüpheli (suspect) in the first phase and a sanık (accused) in the second.

This guide follows a Turkish criminal file from the opening of an investigation to the last available appeal: who decides what, which measures may be applied while the file is open, what happens when the prosecutor chooses between an indictment and a decision not to prosecute, and how the two appellate routes — istinaf and temyiz — differ.

All article and duration references below are to the consolidated text of Law No. 5271 published by the Presidency’s Mevzuat Bilgi Sistemi and consulted on 25 July 2026, whose amendment table runs to Law No. 7571 of 24 December 2025, in force on 25 December 2025. That matters more than it sounds: several of the most frequently quoted periods in Turkish criminal procedure changed as recently as 1 June 2024, and superseded figures are still repeated widely.

The investigation phase (soruşturma)

The investigation is run by the public prosecutor (Cumhuriyet savcısı). Under CMK Art. 160/1 he must begin investigating immediately on learning, through a complaint or by any other means, of a situation giving the impression that an offence has been committed, in order to decide whether there are grounds to open a public prosecution.

The obligation that follows is the one foreign readers most often misunderstand. Art. 160/2 requires the prosecutor, acting through the judicial police under his command, to collect and preserve evidence both for and against the suspect and to protect the suspect’s rights. He is not, at this stage, a party trying to secure a conviction. Art. 161/2 completes the picture: judicial police officers must report apprehended persons and the measures taken to him immediately, and carry out his orders relating to the judicial process without delay.

Everything in the investigation phase is provisional. No court has yet been seised of the case and no charge has been formally laid — yet the şüpheli already holds defence rights, from the first questioning rather than the first hearing.

Because this is where liberty is most often at stake, it is also where the three measures below are applied. Which of them is on the table, and who has power to order it, is usually the first practical question in any file handled by a criminal law practice.

Custody, detention and judicial control compared

Turkish law keeps three quite different measures apart, and English-language accounts routinely conflate them. Gözaltı is short police custody. Tutuklama is detention on remand ordered by a judge. Adli kontrol is a set of obligations imposed instead of detention.

Measure	Who decides	Duration limits under the Code	Article
Gözaltı (police custody)	The public prosecutor; law-enforcement chiefs designated by the civil administration only in the narrow in flagrante cases	At most 24 hours from apprehension, excluding transfer time to the nearest judge or court, itself capped at 12 hours; extendable in writing by up to 3 days, each single extension at most 1 day, only for offences committed collectively	CMK 91/1, 91/3, 91/4
Tutuklama (detention on remand)	The sulh ceza hâkimi on the prosecutor’s request during the investigation; the trial court, on request or of its own motion, during the trial	Outside assize-court jurisdiction: at most 1 year, extendable by 6 months. Within it: at most 2 years, with extensions totalling at most 3 years — 5 years for the offence groups named in Art. 102/2. A separate, shorter cap applies in the investigation phase under Art. 102/4. Halved or reduced to three-quarters for children (Art. 102/5)	CMK 100–102
Adli kontrol (judicial control)	The sulh ceza hâkimi on the prosecutor’s request during the investigation; the competent judicial authority during the trial	Outside assize-court jurisdiction: at most 2 years, extendable by 1 further year. Within it: at most 3 years, with extensions totalling at most 3 years — 4 years for the offence groups named in Art. 110/A. Halved for children	CMK 109–110/A

Gözaltı — police custody

CMK Art. 91/1 sets the basic rule: custody may not exceed twenty-four hours from the moment of apprehension, excluding the time necessarily spent transferring the person to the nearest judge or court, and that transfer time may not itself exceed twelve hours. Custody is not automatic — under Art. 91/2 it depends on the measure being necessary for the investigation and on concrete evidence showing suspicion that the person committed the offence, wording deliberately tightened in 2014 from the earlier and vaguer “signs suggesting”.

Two qualifications matter. Art. 91/3 allows the prosecutor, for offences committed collectively where collecting evidence is difficult or the suspects are numerous, to order in writing an extension for three days, each single extension not exceeding one day, served on the person immediately. Art. 91/4 creates a narrow separate regime, limited to in flagrante situations and a closed list of offences, under which law-enforcement chiefs designated by the civil administration may order custody of up to twenty-four hours — and up to forty-eight hours during social events where spreading violence seriously disturbs public order, and for offences committed collectively.

Behind all of this sits Article 19 of the Constitution (Law No. 2709): an apprehended or arrested person must be brought before a judge within at most forty-eight hours, and within at most four days for offences committed collectively, excluding the time needed to send him to the nearest court. Beyond those periods nobody may be deprived of liberty without a judge’s decision.

Custody is challengeable while it runs. Under Art. 91/5 the apprehended person, his defence counsel or legal representative, his spouse, or a blood relative of the first or second degree may apply to the sulh ceza hâkimi for immediate release; the judge decides on the file immediately, and in any event before twenty-four hours have elapsed. If the person is not released, Art. 91/7 requires him to be brought before that judge at the latest at the end of those periods and questioned, with defence counsel present.

Tutuklama — detention on remand

CMK Art. 100/1 permits detention only where there is concrete evidence showing strong suspicion of the offence and a statutory ground for detention exists; it is excluded where it would be disproportionate to the importance of the matter or to the expected sentence or security measure. The grounds are in Art. 100/2: concrete facts indicating flight, hiding or a risk of flight, or conduct raising strong suspicion of destroying, concealing or altering evidence or of attempting to pressure witnesses, victims or others. Art. 100/3 adds a catalogue of offences for which a ground may be assumed where strong suspicion based on concrete evidence exists. Conversely, Art. 100/4 prohibits detention altogether for offences carrying only a judicial fine, and for offences whose upper limit of imprisonment is not more than two years — the latter exception not applying to offences committed intentionally against bodily integrity.

Who may order it is equally strict. Under Art. 101/1 detention of a suspect during the investigation is ordered by the sulh ceza hâkimi on the prosecutor’s request; during the trial, by the court on the prosecutor’s request or of its own motion. The request must give reasons and set out why judicial control would be inadequate. Art. 101/2 then requires the decision itself — ordering detention, continuing it, or refusing release — to justify expressly and specifically, on concrete facts, the strong suspicion, the ground for detention, the proportionality of the measure and the inadequacy of judicial control; its content is communicated orally and a written copy given to the person. A defence lawyer, chosen or assigned by the bar, is available where detention is requested (Art. 101/3), and decisions under Arts. 100 and 101 are open to objection (Art. 101/5).

Detention is capped, but not by a single headline figure. The ceilings in Art. 102 are layered by the court’s jurisdiction, by phase, by offence group and by age, as summarised in the table above; the longest — extensions of up to five years — is reserved for the offences defined in Book Two, Part Four, Chapters Four to Seven of the Turkish Penal Code and for offences under the Anti-Terror Law No. 3713. Two features are easily missed: Art. 102/4 sets a separate, shorter cap for the investigation phase specifically, and Art. 102/5 applies all these periods at one-half for children who had not completed fifteen years of age at the time of the act and at three-quarters for those who had not completed eighteen. Extensions are decided only after the opinions of the prosecutor, the suspect or accused and defence counsel have been obtained (Art. 102/3).

Detention must also be revisited constantly. Under Art. 108/1, during the investigation the continued need for detention is reviewed at intervals of at most thirty days by the sulh ceza hâkimi on the prosecutor’s request, applying the Art. 100 criteria and after hearing the suspect or his counsel; Art. 108/2 lets the suspect request such a review as well. In the trial phase, Art. 108/3 requires the court to review the detained accused’s position of its own motion at each hearing, between hearings where circumstances require, or within the same thirty-day period.

Adli kontrol — judicial control

Judicial control is the alternative Art. 101/1 obliges the prosecutor to address before asking for detention at all. Under CMK Art. 109/1, where the Art. 100 grounds exist the suspect may instead be placed under judicial control; Art. 109/2 allows the same provisions even where detention is statutorily prohibited. Art. 109/3 lists the obligations, one or more of which may be imposed: not leaving the country; reporting regularly to places designated by the judge; complying with control measures on summonses and, where necessary, occupation or education; not driving and, where necessary, surrendering the driving licence against receipt; submitting to treatment or examination, including hospitalisation, notably for addiction; depositing a security sum fixed by the judge; not possessing or carrying weapons and surrendering them to judicial custody; providing security in kind or personal security for the victim’s rights; giving an undertaking on family obligations and maintenance payments; not leaving one’s dwelling; not leaving a specified area of residence; and not going to specified places or areas.

Time under judicial control is generally not treated as a restriction of personal liberty and is not deducted from a later sentence. Art. 109/6 carves out two exceptions — the treatment or examination obligation and the obligation not to leave one’s dwelling — and counts every two days of house confinement as one day in that deduction.

Judicial control is imposed during the investigation at any stage by the sulh ceza hâkimi on the prosecutor’s request (Art. 110/1) and by the competent judicial authorities during the trial (Art. 110/3), and its continued necessity must be reviewed at intervals of at most four months (Art. 110/4). Since 1 January 2022, Art. 110/A has given judicial control express maximum durations of its own, so it is no longer an open-ended status.

The decision point: indictment or non-prosecution

Every investigation ends in one of two ways.

If the prosecutor finds insufficient grounds, he issues a decision that there are no grounds for prosecution (kovuşturmaya yer olmadığına dair karar, commonly abbreviated KYOK). Under CMK Art. 172/1 this is the outcome where no evidence sufficient to create adequate suspicion for opening a prosecution has been obtained, or where prosecution is not possible. It is notified to the person injured by the offence and to a suspect previously questioned or interrogated, and it must itself state the right of objection, the period for exercising it and the authority to which it lies. A suspect held under detention or judicial control is released when such a decision is given (Art. 103).

The objection route and its deadline are precise. Under Art. 173/1 the person injured by the offence may object within two weeks of the date the decision was served on him, before the sulh ceza hâkimliği located at the seat of the ağır ceza mahkemesi in whose judicial district the deciding prosecutor serves. Both elements of that sentence are frequently misstated: the period was fifteen days until Law No. 7499 replaced it with two weeks with effect from 1 June 2024, and the reviewing authority has been the sulh ceza hâkimliği — not an assize court — since 28 June 2014.

The petition must set out the facts and evidence capable of requiring a prosecution. The sulh ceza hâkimliği may ask the local chief public prosecutor’s office to widen the investigation; if it finds insufficient grounds it rejects the request with reasons, orders the objector to pay the costs and returns the file to the prosecutor, who notifies the decision to the objector and the suspect. If it upholds the objection, the prosecutor draws up an indictment and submits it to the court (Art. 173/2–4).

The decision also protects the suspect. Under Art. 172/2, once it has been given no prosecution may be opened for the same act unless new evidence sufficient to create adequate suspicion is obtained and the sulh ceza hâkimliği has so decided; Art. 173/6 applies the same rule where an objection is rejected. Separately, Art. 172/3 allows the investigation to be reopened on request made within three months of that judgment becoming final, where the European Court of Human Rights has established by final judgment that the decision was given without an effective investigation, or where the application ended in a striking-out following a friendly settlement or unilateral declaration.

If the prosecutor finds sufficient grounds, he files an indictment with the competent court — and the court’s reaction is the hinge on which the case turns. Under Art. 174/1 and 174/3 the court has fifteen days from delivery of the indictment and the investigation file to return it to the prosecutor’s office for the listed defects; an indictment not returned within that period is deemed accepted. Notably, Art. 174/2 forbids returning an indictment merely because of the legal characterisation of the offence — classification is for the trial court to settle, not a reason to send the file back.

The trial phase (kovuşturma)

CMK Art. 175/1 marks the transition in a single sentence: the public prosecution (kamu davası) is deemed opened, and the kovuşturma phase begins, upon the court’s acceptance of the indictment. From that point the court, not the prosecutor, runs the proceedings; under Art. 175/2 it fixes the hearing date and summons those who must attend. The şüpheli becomes a sanık and remains one until the judgment becomes final.

Several safeguards continue to operate, but shift hands. Detention is now ordered, continued or lifted by the trial court (Art. 101/1), which must review the detained accused’s position of its own motion at each hearing or within the thirty-day period (Art. 108/3). Judicial control is likewise reviewed by the court of its own motion at intervals of at most four months (Art. 110/4). A request for release, under judicial control or outright, may be made by the accused or defence counsel at any point (Art. 103).

Two general rules shape what the file looks like from outside. Art. 34/1 requires all decisions, including dissenting opinions, to be written with reasons, and Art. 34/2 requires every decision to state the remedy available against it, its period, the authority to which it lies and the form it must take. Art. 35/2 requires decisions against which a remedy lies — other than those on protective measures — to be served on an interested party who was not present. That is why the appeal clock below is tied to service rather than to what was said in the courtroom.

It is worth being clear about what the criminal process is not for. A commercial grievance does not become a crime because the money is unpaid: an unpaid invoice is pursued through debt collection and enforcement proceedings, and a wide range of civil and commercial claims must first pass through mandatory mediation before any court will hear them. Where the dispute is genuinely commercial it belongs to the commercial litigation and arbitration track rather than to the CMK.

Appeals: objection, istinaf and temyiz

Turkish criminal procedure distinguishes between challenging a decision (karar) taken along the way and challenging the judgment (hüküm) that ends the case.

Objection (itiraz)

Under CMK Art. 267 an objection lies against decisions of a judge, and against decisions of a court in the cases indicated by law. Art. 268/1 sets the period: unless the law provides otherwise, the objection is made within two weeks from the day the interested parties learned of the decision, by petition to the authority that gave it or by a declaration recorded in a minute. This period, too, was seven days until Law No. 7499 replaced it with two weeks on 1 June 2024. The deciding judge or court corrects its own decision if the objection is well-founded and otherwise sends the file to the reviewing authority within at most three days (Art. 268/2).

Art. 268/3 allocates review, and one allocation is often reported incorrectly. As a rule, objections against a sulh ceza hâkimliği’s decisions are reviewed by the next-numbered sulh ceza hâkimliği in the same place; but objections against its decisions on detention and judicial control go to the asliye ceza mahkemesi judge in whose judicial district it sits — a rule introduced by Law No. 7331 and in force since 1 January 2022. Objections against asliye ceza decisions go to the ağır ceza mahkemesi of that district, and objections against ağır ceza decisions to the next-numbered chamber.

An objection does not of itself suspend enforcement, though the deciding or reviewing authority may order suspension (Art. 269). It is as a rule decided without a hearing (Art. 271/1), and the reviewing authority’s decision is final — except that where that authority itself orders detention for the first time, that order is open to objection (Art. 271/4). Where a prosecutor’s opinion is taken on an objection concerning detention, it must be communicated to the suspect, accused or defence counsel, who may respond within three days (Art. 270/2).

İstinaf — appeal to the bölge adliye mahkemesi

CMK Art. 272/1 opens the first appellate route: judgments of first-instance courts may be appealed to the bölge adliye mahkemesi (regional court of appeal), and judgments imposing fifteen years’ imprisonment or more are reviewed by that court of its own motion. Decisions given before the judgment that form its basis, or for which no other remedy is provided, are appealed together with it (Art. 272/2).

Some judgments are excluded. Art. 272/3 shuts the route to convictions to a judicial fine of up to and including 15,000 Turkish lira as finally determined, other than fines converted from imprisonment; to acquittals for offences carrying a judicial fine whose upper limit does not exceed five hundred days; and to judgments stated by law to be final. Judgments given this way do not count for recidivism. The 15,000 lira figure has applied since 1 June 2024, when Law No. 7499 raised it from 3,000 — and, unlike several monetary limits elsewhere in Turkish procedural law, it carries no annual revaluation clause in the CMK, so it changes only when the legislature amends the article.

The deadline is two weeks, and it runs from a specific event. Under Art. 273/1 the istinaf application is made within two weeks from the date on which the judgment together with its reasoning was served, by petition to the court that gave it or by declaration to the clerk. This replaced the former rule of seven days from pronouncement on 1 June 2024, and the difference is substantive rather than cosmetic: the clock now starts when the reasoned judgment reaches the party, which is why the service record is worth keeping. Prosecutors attached to ağır ceza mahkemeleri may appeal asliye court judgments in their district within two weeks of the decision reaching that office, stating their grounds in writing; the application is served on the interested parties, who have two weeks to reply (Art. 273/3 and 273/5).

What the regional court then does is set out in Arts. 279 and 280. On preliminary examination it forwards the file if it lacks jurisdiction, or rejects the appeal as out of time, as directed against a decision not open to istinaf, or as brought by someone with no right to appeal — and those rejections are themselves open to objection. On the merits it may reject the appeal; reject it after correcting the unlawfulness in the listed cases; quash the judgment and send the file back where an absolute ground of unlawfulness under Art. 289 exists or a condition of investigation or prosecution was not met; or, in other cases, retry the case itself, ending either by rejecting the appeal on the merits or by setting aside the first-instance judgment and giving a new one. That ability to re-examine the facts is what distinguishes istinaf from the route above it.

Temyiz — appeal on points of law to the Yargıtay

CMK Art. 286/1 allows judgments of the criminal chambers of the bölge adliye mahkemesi, other than quashing (bozma) decisions, to be appealed on points of law to the Yargıtay (Court of Cassation). The route is far from universal: Art. 286/2 lists categories that cannot be taken further, including regional-court decisions rejecting on the merits an appeal against sentences of five years’ imprisonment or less and against judicial fines of any amount, and decisions that do not increase such sentences of five years or less. Art. 286/3 then cuts back across those exclusions for a closed list of offences — among them aggravated insult (TPC Art. 125/3), incitement to commit an offence (Art. 214), praising an offence or offender (Art. 215), incitement to hatred and enmity (Art. 216), public dissemination of misleading information (Art. 217/A), insulting the President (Art. 299) and armed organisation (Art. 314), together with specified offences under the Anti-Terror Law and the Law on Meetings and Demonstrations.

The period mirrors istinaf: under Art. 291/1 the temyiz application is made within two weeks from the date on which the judgment together with its reasoning was served. Under Art. 298 the Yargıtay rejects the application where it was out of time, where the judgment is not open to temyiz, where the applicant had no right to appeal, or where the petition contains no grounds. For judgments involving ten years’ imprisonment or more, Art. 299/1 permits the Yargıtay, if it sees fit, to examine the case by way of a hearing, notice of which is given to the accused, the intervening party and their lawyers.

Art. 260/1 opens all of these remedies to the public prosecutor, the suspect, the accused, those who have acquired the status of intervening party (katılan), and those whose intervention request was not decided or was rejected, or who were injured by the offence in a way that would allow them to become an intervening party. Under Art. 260/3 the prosecutor may also use remedies in favour of the accused, and under Art. 261 a lawyer may use them provided this is not contrary to the express wish of the person he represents.

Rights of a suspect

The Code front-loads defence rights into the first questioning rather than the first hearing. CMK Art. 147/1 requires, whenever a statement is taken or a person is interrogated, that:

• his identity is established, and he must answer identity questions truthfully;
• the offence alleged against him is explained;
• he is told he may choose a defence lawyer and benefit from that lawyer’s assistance, that the lawyer may be present during the statement or interrogation, and that if he cannot appoint one and wishes legal assistance, a lawyer will be assigned by the bar;
• a relative of his choice is informed immediately of his apprehension;
• he is told that it is his legal right not to make a statement about the alleged offence;
• he is reminded that he may request the collection of concrete evidence to clear himself, and is given the opportunity to rebut the grounds of suspicion and raise matters in his favour.

Art. 148 protects the integrity of that statement: it must rest on free will, and ill-treatment, torture, administration of drugs, exhaustion, deception, physical force, threats and the use of certain devices are prohibited, as is promising an unlawful benefit. Statements obtained by prohibited methods cannot be used as evidence even if given with consent. And Art. 148/4 provides that a statement taken by law enforcement without a defence lawyer present cannot be the basis of a judgment unless the suspect or accused confirms it before a judge or court — a rule narrower than the “invalid statement” shorthand often used to describe it, and worth reading exactly as written.

Access to counsel is broad. Art. 149 gives the suspect or accused one or more defence lawyers at every stage of both phases; at most three may be present when a statement is taken during the investigation; and the lawyer’s right to meet the person, to be present throughout, and to give legal assistance may not be obstructed or restricted at any stage. Art. 150 adds assignment on request where the person declares he cannot choose a lawyer, and without any request where he has none and is a child, is disabled to a degree preventing self-defence, or is deaf and mute — and likewise for offences whose lower limit exceeds five years’ imprisonment. Language is dealt with in Art. 202, whose court-appointed interpretation extends to suspects, victims and witnesses heard during the investigation, with interpreters drawn from lists compiled annually by the provincial judicial justice commissions; the additional facility in Art. 202/4 is expressly not funded by the State Treasury and may not be used to protract proceedings.

For a foreign national the criminal file rarely stands alone. A conviction is among the grounds on which a removal decision may be issued under the Law on Foreigners and International Protection No. 6458, so the consequences described in our guide to deportation in Türkiye often need to be considered alongside the criminal proceedings rather than after them.

Why the periods matter more than the labels

Read as a whole, CMK No. 5271 is a code of deadlines. Twenty-four hours of custody. Fifteen days for a court to return an indictment. Thirty days between detention reviews. Four months between judicial-control reviews. Two weeks to object, two weeks for istinaf, two weeks for temyiz — the last two running from service of the reasoned judgment rather than from the moment it was pronounced. Most were amended within the last few years, and the older figures remain in wide circulation.

That is the practical reason to check the current text of the Code, published in the Resmî Gazete and in the Mevzuat Bilgi Sistemi database referred to above, rather than relying on a summary of unknown vintage. Anyone facing or observing a criminal process in Türkiye should also take legal advice early, since the rights described here — silence, counsel, review of detention, objection — are worth most while the file is still open and least once a period has expired.