Taking statements and interrogating illegally is regulated in article 148 of the Criminal Procedure Law. When we examine the article, first of all, the statement of the suspect-defendant should be based on the free will of taking a statement and interrogating. Prohibited methods can be understood as any "physical or mental intervention". At the same time, taking a statement with an unlawful promise is among the prohibited methods.
The CPL has introduced a new evidence evaluation ban that was not included in the old CPL. The defense counsel has an important role in taking statements. According to Article 148/4 of the CMK, a statement taken by law enforcement without a lawyer does not constitute evidence unless it is verified by the judge or the court. Unless the accused or the suspect states that he has verified his statement before the judge or the court, the statements taken without a lawyer cannot be taken as basis in the prosecution phase.
If there is only the statement of the accused or suspect as evidence about the crime imposed on the accused or suspect, this statement cannot be counted as evidence if it is taken without a defense counsel or if it is not confirmed by the judge or the court. The court ex officio takes into consideration whether the evidence has been obtained in accordance with the law.
Since the statements obtained in this way cannot be considered as evidence, they must be rejected. The fact that the verdict is based on the statement taken by such methods is considered an absolute violation of the law and is the reason for the reversal.
Court of Cassation Decisions within the Scope of 148/4
“In the concrete case, although the defendant admits that he insulted the participant in his law enforcement statement, this statement was not taken before the defense counsel, the defendant did not confirm this statement at the court of instruction, therefore the law enforcement statement of the defendant was taken as a basis without considering that the law enforcement statement cannot be read at the hearing and the verdict cannot be taken as basis ...” (4th Criminal Chamber Case No: 2020/10632 , Decision No:2020/18317)
“In terms of the judgment established on the offense of theft against the participant ..., the defendant ... stated that he committed the theft action against the participant twice in his defense, which was taken without a defense law enforcement during the investigation phase. During the trial, there was no further evidence that the defendant committed the act more than once, taking into account Article 148/4 of the CPL, as he declared that he committed the crime of theft once against the participant and denied his statement of the law enforcement attorney. Establishing a written provision by increasing the penalty pursuant to Article 43 of the TCC numbered 5237 ...” (17th Criminal Chamber Case No: 2016/14141, Decision No: 2018/13602)
“Although the statement of the defendant, taken by law enforcement without the presence of a lawyer, stated that he had declared that the smuggled cigarettes found on the bus belonged to him, the court did not accept the allegation. In this case, considering that the law enforcement statement cannot be based on the verdict in accordance with paragraph 4 of Article 148 of the CMK; While the local court should listen to the bus driver and his assistant as witnesses about whether the cigarettes subject to crime belong to the defendant, and all evidence should be evaluated together and the legal status of the accused should be determined according to the result, it is inaccurate to establish a verdict with an incomplete investigation.” ...” (Criminal General Board Case No: 2013/309, Decision No: 2016/375)