Confession has not been defined neither in the Evidence Act nor in the Code of Criminal Procedure. Stephen in his digest "Law of Evidence" defined confession as an admis­sion made by a person charged with crime stating or suggesting the inference that he committed the crime. Confession as to the meaning of "Confession" was noted by the Privy Council in the case of Pakala Narayan Swami Vs. King Emperor reported in AIR 2939 PC 47(52) wherein Lord Atkin observed that "No statement containing self exculpatory matter could amount to confession if the exculpatory statement was of some facts which if true could negative the offence alleged to be confessed. Moreover a confession must either admit in terms of the offence or at any rate substantially all which constitute the offence". It is well settled that confession means an admission of certain facts which constitute an offence made by a person who is charged with an offence which is subject-matter of his statement. So confession should be directly on the point of admitting facts. No statement that contains self exculpatory matter amounts to confession. Confession must admission in terms or at rate substantially all facts which constitute the offence (1988 BLD 345), only statement which is direct acknowledgement of guilt amounts to confession… It is well settled that the confession of an accused is not a substantive piece of evi­dence against co-accused who did not confess and such evidence alone without any subs­tantive corroborative evidence cannot form basis of conviction of co-accused. With this regard reliance is being placed in this case of Mofazzal Hossain alias Mofa Vs. State 58 DLR 524. This view receives support in the cases of State Vs. Rafiqullah Khan 7 BLC 480, Ustar Ali Vs. State 3 BLC (AD) 53, Lutfurnahar Vs. State 27 DLR (AD) 29, Babor Ali Molla Vs. State 44 DLR (AD) 10, State Vs. Lalu Mia 39 DLR (AD) 117, Amir Hossain Vs. State 37 DLR (AD) 179, Joygun Bibi Vs. State 12 DLR (SC) 156. 

(17 BLC (HCD) (2012) 307) 

A confession is an admission made at any time by a person charged with a crime, stating or suggesting the inference that he committed that crime. A confession must either admit in terms the offence, or at any rate substantially, all the facts which constitute the offence. In order to decide whether a statement is confessional or not, it must be read as a whole. Prudence and justice demand that such evidence cannot be made the sole ground of conviction. It may be used only as a corroborative piece of evidence. The rule of prudence does not require that each and every circumstance mentioned in the confession with regard to the participation of the accused person in the crime must be separately and independently corroborated, nor is it essential that the corroboration must come from facts and circumstances discovered after the confession was made. Deliberate and voluntary confessions of guilt, if clearly proved, are among the most effectual proofs in law. The Court should apply two tests: Is it voluntary? Is it true? ... The confession of an accused person against a co-accused is not evidence in the ordinary sense of the term. Such a confession can only be used to lend assurance to other evidence against a co-accused. The judge may call in aid the confession and use it to lend assurance to the other evidence. According to section 24 of the Evidence Act, a confession by an accused is irrelevant if it is caused by inducement, threat or promise.

A confession is relevant-

(1) if it is made after the impression caused by any such inducement, threat or promise has been fully removed;

(2) if it is not made to a police officer; or

(3) if it is made in the presence of a Magistrate when the accused is in the custody of a police officer. 

(Khalil @ Khalilur Rahman and others Vs. State, 2008, 37 CLC (HCD) [6743]) 

The confessional state­ment of an accused is not substantive piece of evi­dence against the one who did not confess and such evidence alone, without any substantive corrobora­tive evidence cannot form the basis of conviction of co-accused. 

(State Vs. Delwar Hossain & others, 2011, 40 CLC (HCD) [8129])  

Learned Assistant Sessions Judge erred in law in admitting the confessional statement of a co-accused as substantive evidence against the accused-appellant. 

(Mojibar Vs. State, 1998, 17 CLC (HCD) [5602])

Confessional statement of an accused can be relied upon for the purpose of conviction and no further corroboration is necessary if it relates to the confessing accused himself provided the confession is true and voluntary. For finding out whether Judicial confessional statement is truthful or not there must be some reliable, independent and corroborative evidence. Before solely relying upon the confessional statement, Court has to find out whether it is made voluntarily or truthfully by the accused. Even if it is made voluntarily the Court has to decide whether it is made truthfully or not. Voluntary means that one, who makes it out of his own free will, inspired by the sound of his own conscience. If the facts and circumstances surrounding the making of a confession appear to fling a doubt on the voluntariness and truthfulness of the confession, the Court is to refuse to act upon the confession, even if it is admissible in evidence. The question whether a confession is voluntary or not is always a question of fact. 

(13 MLR (HCD) (2008) 88) 

A statement made by a person accused of an offence, by which his guilt is acknowledged or from which it can be inferred. Confession is the acknowledgment by a criminal of the offence charged against him, when charged by any person or called upon to plead to the indictment. A confession before trial, if given without any inducement in favour or threat of punishment, is evidence against the person charged even though he may be in custody. A confession means an admission of certain facts constituting an offence committed by a person who is charged for the offence which is the subject matter of the statement. 

(State Vs. Monu Meah and others, 6 BLC 402)

To be the basis of conviction a confession must be voluntary and true and it must also be inculpatory in nature. A retracted confession requires independent and reliable corroboration before it is accepted and acted upon. Confession of a co-accused is no evidence against other accused persons. It may, however, lend assurance to other evidence – the Evidence Act 1872, Sections 24-30. 

(Dual Miah alias Nurul Islam and others Vs. The State, 14 BLD (HCD) 477)

See, sections 24 to 30, the Evidence Act, 1872.