Extra-judicial confession is a weak piece of evidence. If it is lacking in probability, there is no difficulty in rejecting it.

For testing the credibility of extra-judicial confession, the Court will consider

(i) The circumstances in which the extra-judicial confession is made;

(ii) The manner in which it is made;

(iii) The person to whom it is made along with the rules of caution.

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—

(i) If it is made after the impression caused by any such inducement, threat, promise has been fully removed (section 28);

(ii) If it is not made to a police officer (s. 25), or

(iii) If it is made in presence of a Magistrate when the accused is in the custody of a police officer (section 26).

Before a confession can be accepted in evidence, it must be established by cogent evidence that what were the exact words used by the accused. Even if so much is established, 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 circumstances 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 the facts and circumstances discovered after the confession was made.

The Court should apply two tests:

Is it voluntary? Is it true? It is the duty of the Court to enquire very carefully into all the circumstances under which confession was made and to ascertain whether it is true and voluntary. 

(Abdul Hannan Vs. State, 2008, 37 CLC (HCD) [8064])