A confession, proved as an exception to the rule against hearsay, is admissible as evidence of the truth of the matters adverse to the accused contained therein, if relevant to any matter in issue. It may, if the court thinks right, be relied upon to convict, even in the absence of other evidence. As Erie .J. said in R .v. Baldry1 “a confession well proved is the best evidence that can be produced". Because the weight of a confession is a question of fact, the court of Appeal will rarely interfere with a conviction based upon such evidence, even where it is unsupported by other evidence. However, where the terms of the confession are such that no reasonable court could safely draw the necessary inference of guilt from it, the conviction may be quashed as being unsafe and unsatisfactory.
Confessions are subject to the rule regarding admissions generally that the whole statement must be put before t he court, to be looked at as a whole and in context. This means that where a statement is partly, adverse to, and partly favourable to the accused, he is entitled to have both placed before the court, although this may cause problems of evidential value. But there are occasions when confessions should be placed before the court in an 'edited' form, in order to prevent the court from being exposed to prejudicial and inadmissible material. When a confession is made, it is important that it should be recorded in accuser's words, exactly as it is made. At common law, it is a fundamental principle of the use of admissions and confessions that an admission or confession is evidence against the maker of the confession only, and not against any other person implicated by it. Section 27(3)2 provides that where more than one persons are charged jointly with a criminal offence and a confession made by one of such persons in the presence of one or more of the other persons so charge is given in evidencewith a jury, shall not take such statement into consideration as against; any of such, other persons in whose presence it was made unless he adopted the said statement by words or conduct. A confession is therefore evidence only against the person who made it and not against his co-accused. A statement made to the police by an accused person is not evidence against a co-accused and a magistrate must warn himself of this fact so that that statement in considering the case against the co-accused will not affect his mind. For the sake of safety and clarity, however, it is desirable that a judge sitting alone should record that he has given himself the proper warning. In R .v. Ume3, an accused person who hard made an extra-judicial confession implicating a co-accused gave evidence at the trial and was brought by leading questions to say that he adopted his statement and had nothing further to add. By adopting the statement he thus made it evidence against him co-accused. The West Africa Court of Appeal, however, held that the trial judge, not having heard the witness tell his story in full and observed his demeanour, was wrong to Convict the co-accused on the strength of his evidence and the conviction was quashed. Although it is desirable to have, outside a confession, some evidence, be it slight, of circumstances which make it probable that the confession was true, yet if a person makes a voluntary confession of guilt, if it is fully consistent and probable, is usually regarded as evidence of the highest and most satisfactory nature if there is an independent proof that a criminal act has in fact been committed by someone and that the accused person had the opportunity of committing the offence, and that the confession was consistent with other facts which had been ascertained and proved. If the court is satisfied with the confessional statement, the accused may be convicted on the confession alone without any further evidence. In James Obi Achabue .v. The state4, the Supreme Court held that confession alone even without corroboration can support a conviction so long as the court is satisfied of the truth. In R .v. Abraham Erumesi5, the accused was charged with the murder of a woman. He had made a statement to the police confessing to the commission of the offence but beyond this there was very little else known by the prosecution of the facts and circumstances surrounding the death of the deceased. As there were other circumstance which showed beyond any reasonable doubt that a criminal act had been committed by someone and as the accuser's confession was fully consistent and probable, it was held that he could be convicted on such a confession..