In Criminal Law, the statements of the suspect or the accused are one of the most important criminal procedure actions where the right to defense is exercised, in addition to the activity of investigating the truth. Therefore, taking testimony and interrogation encompass not only certain obligations but also rights.

During the investigation phase, the process of taking the suspect's statements about the incident by the prosecutor's office or the relevant law enforcement (police, gendarmerie, coast guard) is referred to as testimony. Interrogation, on the other hand, is conducted exclusively by a judge in a court setting. This is the most fundamental distinction between testimony and interrogation.

Giving testimony and being interrogated are activities that involve both rights and obligations for the suspect/accused. The suspect may be called in to give testimony either by applying one of the protective measures, such as arrest, detention, or pretrial detention, or directly by the investigation authorities without applying these measures. When the suspect appears before law enforcement or the public prosecutor to give testimony, they must be immediately informed of their rights and the accusations against them should be explained. From this moment on, the suspect must decide whether to give testimony without a defense counsel (lawyer). If the suspect does not want a defense counsel, they must clearly accept the consequences of this decision.

During the interrogation, the rights that we will explain below must be conveyed to the defendant, and the interrogation should be completed in accordance with the right to defense. In the interrogation conducted by the criminal judgeship of peace or the competent and authorized court, the defendant's right to a fair trial must be respected, the defendant's right to remain silent should not be interpreted as an admission, and prohibited methods listed in the Law should not be used to obtain evidence.

– Suspect – In the investigation phase, the person under suspicion of committing a crime is referred to as a suspect. The investigation phase begins when a person is suspected of a crime.
 
– Defendant  – Refers to the person under suspicion of committing a crime after the prosecutor files an indictment and the prosecution begins in court following the investigation.
                             In short, if there is suspicion of a crime regarding a person, they are referred to as a suspect during the investigation phase and as a defendant during the prosecution phase.

What is the Presence of a Lawyer During Testimony?

As explicitly stated in the relevant law, at every stage of the investigation and prosecution phases, the right of the lawyer to be present with the suspect or defendant during interviews, testimony, or interrogation, and to provide legal assistance, cannot be obstructed or restricted.

When there is no available defense attorney, law enforcement is obligated not to begin taking the suspect’s statement or, if the process has already started, to cease taking the statement. This process continues until a defense attorney is present with the suspect.

According to the Criminal Procedure Code: “A statement taken by law enforcement without the presence of a defense attorney cannot be used as evidence for the judgment unless it is confirmed by the suspect or defendant in the presence of a judge or court.”

The authority of a defense attorney who participates in testimony or interrogation to be present with the suspect and provide legal assistance is not limited to monitoring whether the rights of the suspect or defendant are protected during these processes. It also includes actively providing legal assistance to the suspect or defendant, protecting them from situations that may put them in a difficult position, and taking necessary precautions.
While the defense attorney’s authority includes actively providing legal assistance to the suspect or defendant during testimony and interrogation, this assistance does not extend to answering questions or responding to accusations on behalf of the suspect or defendant. In other words, the legal assistance provided by the defense attorney should not prevent the discovery of the material truth.

However, the lawyer may request a private discussion with the person they represent in response to a question, warn them about issues they consider contentious, provide partial guidance during testimony and interrogation, object to questions, and request that the person exercise their right to remain silent.

As with any legal matter, it is crucial that lawyers fulfill their duties in this regard without overlooking necessary aspects and details, ensuring that the concrete truth is reached.
 
In conclusion, the authority and responsibility of a defense attorney participating in testimony or interrogation to be present with the suspect and provide legal assistance encompass not only overseeing whether the rights of the suspect or defendant are protected during these processes but also actively providing legal assistance to the suspect or defendant, protecting them from situations that may put them in a difficult position, and taking necessary precautions.

What is a Summons for Interrogation or Testimony in an Investigation?

The Public Prosecutor is responsible for conducting the investigation phase. The prosecutor, through the police and gendarmerie officers under their command, carries out the investigation and collects all evidence. All tools used in the crime, reports, statements, complaints, testimonies of the suspect, complainant, and witnesses, and any other evidence related to the investigation are collected by law enforcement (police or gendarmerie).

Law enforcement officers must report to the Public Prosecutor any individuals they have detained on suspicion of committing a crime or any measures they have taken. They cannot take statements or perform other police procedures without instructions from the Public Prosecutor.

Judicial law enforcement officers are required to promptly report any incidents they have seized, the individuals they have detained, and the measures they have taken to the Public Prosecutor they work under, and to immediately comply with all instructions from the Public Prosecutor regarding judicial matters. The Public Prosecutor issues orders to judicial law enforcement officers in writing; in urgent cases, orally. (Criminal Procedure Code, Art. 161/2-3).

Summoning a suspect to provide a statement generally involves inviting them to the police department, gendarmerie, police station, or prosecutor's office. The person to be interviewed is summoned by an official invitation; the reason for the summons is explicitly stated; and it is noted that failure to attend may result in being forcibly brought in (Criminal Procedure Code, Art. 145). In practice, police often use phone calls to summon individuals to provide their statements, as per Article 15 of the Law on Police Duties and Powers (PVSK). The authority to compel a suspect to attend is a power that can be exercised by the Public Prosecutor. Law enforcement cannot apply compulsory attendance measures to obtain statements from complainants or suspects without a decision from the prosecutor during the investigation phase. However, according to Article 36 of the Regulation on the Duties and Powers of the Gendarmerie, the gendarmerie can enforce compulsory attendance for suspects, complainants, and witnesses who fail to appear despite the summons, even without a decision from the prosecutor. It is important to note that if there is a need to take a second statement from the suspect regarding the same incident, this can only be done by the Public Prosecutor; the police or gendarmerie cannot conduct such an interview (Criminal Procedure Code, Art. 148/5).

What is the Compulsory Attendance of a Suspect or Defendant?

A decision for the compulsory attendance of a suspect or defendant can be made if there are sufficient grounds for issuing an arrest warrant or detention order, or if the suspect or defendant fails to appear as summoned. The compulsory attendance decision must explicitly identify the suspect or defendant, specify the crime they are involved in, describe their physical appearance if necessary, and state the reasons for their compulsory attendance. A copy of the compulsory attendance decision is provided to the suspect or defendant.

What is the Duration of Compulsory Detention?

A suspect or defendant summoned by a compulsory attendance decision must be brought before the requesting judge, court, or Public Prosecutor immediately, or if not possible, within a maximum of 24 hours, excluding travel time, and be interrogated or have their statement taken.

When Does Compulsory Attendance Begin and End?

Compulsory attendance begins at a justified time and continues until the interrogation or statement-taking is completed, as determined by the judge, court, or Public Prosecutor.

What Are the Rights of the Suspect During Testimony and Interrogation?

The general rights of the suspect are summarized in Articles 147 and following of the Criminal Procedure Code:

• The suspect or defendant is required to answer questions related to their identity truthfully.

• The suspect must be informed of the crime they are accused of. A suspect or defendant who is unaware of the charges cannot adequately defend themselves. Therefore, the principle of being informed of the accusation is one of the fundamental principles of criminal procedure and ensures the suspect or defendant has the opportunity to defend themselves. If this right is not granted, it means that the defense has not been allowed against the accusation, the method of contradiction has not been applied, and ultimately, a fair trial has not been conducted. The crime charged, the act alleged, location, time, etc., should be outlined in general terms, and the person should be given enough time to exercise their right to defend themselves.

• The suspect has the right to choose a lawyer and benefit from their legal assistance, and the lawyer may be present during testimony or interrogation.

• The person who has been detained must have their relatives informed immediately.

• The suspect is informed that they have the legal right to remain silent and not make statements about the crime they are accused of. The right to remain silent is a general immunity allowing individuals not to make statements that could lead to their punishment or not to answer questions of that nature. The exercise of the right to remain silent does not imply an admission of guilt, and it cannot be used against the suspect as an “evidence presumption” or “presumption of guilt,” as using silence against the suspect as evidence would violate the principles of fair trial and the rule of law. Since silence is one of the ways for the suspect to defend themselves, the right to remain silent should be regarded as a rule.

• The suspect is reminded that they can request the collection of concrete evidence to clear any doubts and be given the opportunity to eliminate reasons for suspicion against them and present favorable evidence. The suspect or defendant has the right to show evidence and request the collection of evidence during the investigation or prosecution phase.

• Information about the personal and financial situation of the person giving a statement or undergoing interrogation is obtained. The suspect or defendant must be asked about their personal and financial situation before the statement or interrogation process begins. The information provided about the personal and financial situation is taken into account by the court in applying personalized measures.

• Technical means are used in recording statements and interrogations.

• The statement or interrogation must be documented in a report. Regardless of where the statement is taken (police station, gendarmerie, or prosecutor’s office), it must be recorded. The report must be signed by the person taking the statement, the person writing it, and the person giving the statement. A copy of the report must be given to the person who provided the statement.
• The suspect or defendant can benefit from the assistance of one or more defense attorneys at any stage of the investigation and prosecution. During the investigation phase, there can be up to three defense attorneys.

• At every stage of the investigation and prosecution, the lawyer’s right to meet with, assist, and be present during the statement or interrogation of the suspect or defendant cannot be restricted or prevented.

As seen, the most fundamental rights of the suspect or defendant are the right to remain silent, the right to legal assistance, and the right to collect evidence in their favor. These rights are crucial for the suspect to address the suspicion of a crime against them. A suspect who makes a false statement about the crime they are accused of and has it recorded might create a criminal admission on their behalf, and later retracting or correcting such a statement may be difficult or impossible in some cases. Such situations can lead to detention and subsequently to the filing of charges. Therefore, it is extremely beneficial for the suspect to be aware of their rights and to act accordingly during the investigation phase.

What Are the Prohibited Methods in Taking Statements and Interrogations?

In our country, Article 148 of the Code of Criminal Procedure No. 5271 regulates "Prohibited Methods in Taking Statements and Interrogations." It states: "The statement of the suspect or defendant must be based on their free will. Physical or psychological interventions such as mistreatment, torture, administering drugs, exhaustion, deception, coercion, threats, or using certain instruments that obstruct free will cannot be used" (Criminal Procedure Code, Article 148/1).

"Statements obtained through prohibited methods, even if given voluntarily, cannot be used as evidence. Statements taken by law enforcement without the presence of a lawyer cannot be used as a basis for judgment unless they are confirmed by the suspect or defendant in the presence of a judge or court" (Criminal Procedure Code, Article 148/3-4).

• Mistreatment: The statement of the suspect or defendant must be based on their free will. Mistreatment refers to actions that harm the mental or physical health of the person. When mistreatment becomes systematic or continuous to a certain extent, it is considered as torture. For example, withholding water or food from a suspect in custody, not allowing them to use the restroom or meet other needs, and exerting pressure through words and actions are considered forms of mistreatment.

• Torture: Torture involves systematic and prolonged actions by a public official that are incompatible with human dignity and cause physical or psychological pain, affect the person's perception or willpower, and lead to humiliation. For example, systematically keeping someone awake to cause sleep deprivation is considered torture. Torture is an assault on the fundamental value of human dignity, and it dehumanizes the individual, instills a sense of humiliation, and violates the inviolable and inalienable values inherent in human beings. Torture is prohibited by Article 17 of the Constitution.

• Administering Drugs: A suspect or defendant cannot be given drugs that could harm their health or affect their freedom of will. The term "administering drugs" refers to substances that impact the physical or mental state of the suspect or defendant and impair their freedom of will. This includes any substance in solid, liquid, or gaseous form administered to the human body, whether ingested, mixed with food or drink, inhaled, injected, or applied to an open area of the body. Common examples include intoxicants, narcotics that weaken resistance, sedatives, or stimulants. Administering drugs can influence the suspect's or defendant's free will in various ways. Such actions are considered prohibited interrogation methods. If a suspect or defendant voluntarily consumes alcohol or drugs, thereby partially or completely diminishing their freedom of will, any subsequent interrogation or statement taken under such conditions would also be considered unlawful.

• Exhaustion: Exhaustion refers to the intentional infliction of physical or mental fatigue to weaken the will of the suspect or defendant, thereby impairing their freedom of will. Actions that deliberately cause physical or psychological exhaustion before or during an interrogation or statement are considered prohibited interrogation methods. For example, starting an interrogation late at night and then transferring the interrogation to other officers on the morning shift without allowing the suspect to rest can lead to fatigue, making the interrogation unlawful due to the undue stress placed on the suspect.

• Deception: Deception involves the use of fraudulent actions by those conducting the interrogation to undermine or distort the free will of the suspect or defendant. It is one of the most controversial and challenging prohibited interrogation methods. Deception includes presenting false scenarios as real or providing incorrect information about the legal or factual situation to hinder the suspect's or defendant's ability to freely form their own will. For instance, misleading a suspect by falsely claiming that a severe penalty will be imposed if they do not cooperate, or that their sentence will be reduced if they provide a certain statement, constitutes unlawful deception. Intentionally misleading a suspect during interrogation to induce specific responses or beliefs is prohibited.

• Coercion or Threats: Coercion or threats during interrogation are explicitly prohibited methods under Article 148 of the Criminal Procedure Code. Coercion involves using physical force to compel a suspect or defendant to act in a certain way. Threats involve suggesting to the suspect or defendant that a negative outcome, which depends on the will of the person making the threat, will occur in the future if they do not comply. For example, threatening that the suspect's or defendant's family will be harmed if they do not provide a confession or a specific statement constitutes a threat and is thus prohibited.

• Use of Certain Tools and Techniques: The use of lie detectors (polygraphs) and hypnosis is prohibited in interrogation. Lie detectors are considered contrary to human dignity, while hypnosis carries the risk of misuse. Consequently, both methods are deemed unlawful for obtaining statements or confessions.

“T.C.
YARGITAY
6. CEZA DAİRESİ
ESAS NO: 2010/30146
KARAR NO: 2011/6501
KARAR TARİHİ: 05.05.2011

ÖZET: Türkiye Cumhuriyeti Anayasası’nın 38/6 maddesi uyarınca Kanuna aykırı olarak elde edilmiş bulgular, delil olarak kabul edilemez hükmü ile 5271 sayılı CMK.nun 148/. ve 5. fıkralarında yer alan Müdafi hazır bulunmaksızın kollukça alınan ifade, hâkim veya mahkeme huzurunda şüpheli veya sanık tarafından doğrulanmadıkça hükme esas alınamaz ve şüphelinin aynı olayla ilgili olarak yeniden ifadesinin alınması ihtiyacı ortaya çıktığında, bu işlem ancak Cumhuriyet Savcısı tarafından yapılabilir, hükümlerine aykırı şekilde sanığın başkaca kesin, yeterli, inandırıcı ve hukuki kanıtlarla desteklenmeyen kolluk anlatımının hükme esas alınarak sanığın atılı suçlardan beraatı yerine yazılı şekilde cezalandırılmasına karar verilmesi kanuna aykırıdır.”
(5271 s. Ceza Muhakemesi K m. 148, 253)

“YARGITAY İLAMI
YEREL MAHKEMECE verilen hüküm temyiz edilmekle; başvurunun nitelik, ceza türü, süresi ve suç tarihine göre dosya görüşüldü:
Diğer temyiz itirazları YERİNDE GÖRÜLMEMİŞTİR.
Ancak;

1- Sanık N. Ö.’nün kollukta savunmanı olmadan alınan 02.11.2007 günlü ilk ifadesinde atılı suçlamaları kabul etmediği, aynı sanığın gene kollukta savunmanı olmadan alınan 28.11.2007 günlü ikinci ifadesinde ise hırsızlık ve iş yeri dokunulmazlığını bozmak suçlarını işlediğine dair detaylı anlatımda bulunduğu, sanığın bu eylem nedeniyle C. Savcısınca ifadesinin alınmadığı, tutuklama istemli olarak Sulh Ceza Mahkemesi’ne sevk edildiği, 29.11.2007 günlü Zonguldak 1. Sulh Ceza Mahkemesi’ndeki sorgusunda ise atılı suçlamaları kabul etmediği, kamu davası açılması üzerine Zonguldak 2. Asliye Ceza Mahkemesi’nin 08.01.2008 günlü celsesinde alınan savunmasında atılı suçlamaları kabul etmediği ve dosyada sanığın atılı suçu işlediğine dair kollukta savunmanı bulunmadan alınan ikinci ifadesindeki ikrarı dışında da kesin, yeterli, inandırıcı ve hukuki bir kanıt bulunmadığının anlaşılması karşısında Türkiye Cumhuriyeti Anayasa’nın 4709 Sayılı Kanunla değişik 38/6 maddesi uyarınca “Kanuna aykırı olarak elde edilmiş bulgular, delil olarak kabul edilemez.” hükmüyle 5271 sayılı CMK.nun 148/4. ve 5 inci fıkralarında yer alan “Müdafi hazır bulunmaksızın kollukça alınan ifade, hakim veya mahkeme huzurunda şüpheli veya sanık tarafından doğrulanmadıkça hükme esas alınamaz.” ve “Şüphelinin aynı olayla ilgili olarak yeniden ifadesinin alınması ihtiyacı ortaya çıktığında, bu işlem ancak Cumhuriyet Savcısı tarafından yapılabilir.” hükümlerine aykırı şekilde sanığın başkaca kesin, yeterli, inandırıcı ve hukuki kanıtlarla desteklenmeyen kolluk anlatımının hükme esas alınarak sanığın atılı suçlardan beraati yerine yazılı şekilde cezalandırılmasına karar verilmesi,

2- Sanık M. T. yönünden ise diğer sanık N. Ö.’nün yukarıda anılan ve hukuken bir değer kazanmayan ikrarı dışında atılı suçu işlediğine dair kesin, yeterli, inandırıcı ve hukuki bir kanıt bulunmadığı halde sanığın atılı suç eşyasını satın almak suçundan beraati yerine yazılı şekilde cezalandırılmasına karar verilmesi,

Kabul ve uygulamaya göre de;

3- Sanık N. Ö. üzerine atılı işyeri dokunulmazlığını bozmak suçunun suç tarihi itibariyle (5918 s. Kanunla değişiklikten önceki) 5271 sayılı CMK.nun 253 üncü maddesi uyarınca uzlaşma kapsamında suçlardan olduğu gözetilmeden uzlaşma usulü uygulanmadan yazılı şekilde hüküm kurulması,
Bozmayı gerektirmiş, sanık N. Ö. ile sanık M. T. savunmanının temyiz itirazı bu bakımdan yerinde görülmüş olduğundan, hükmün açıklanan nedenlerle isteme aykırı olarak BOZULMASINA, bozma gerekçesine göre de sanık N. Ö.’nün TAHLİYESİNE, başka bir suçtan tutuklu yada hükümlü değilse derhal salıverilmesi için YARGITAY Cumhuriyet Başsavcılığına yazı yazılmasına 05.05.2011 tarihinde oy birliğiyle karar verildi.”
Ceza Yargılamasında usuli işlemlerin önemi ve sonuçları değerlendirildiğinde, etkili bir savunma için alanında uzman bir ceza avukatından destek almak büyük önem arz etmektedir.