The rule on res inter alios acta provides that the rights of a party cannot be prejudiced by an act, declaration, or omission of another. Consequently, an extrajudicial confession is binding only on the confessant, is not admissible against his or her co-accused and is considered as hearsay against them. The reason for this rule is that:
“On a principle of good faith and mutual convenience, a man’s own acts are binding upon himself, and are evidence against him. So are his conduct and declarations. Yet it would not only be rightly inconvenient, but also manifestly unjust, that a man should be bound by the acts of mere unauthorized strangers; and if a party ought not to be bound by the acts of strangers, neither ought their acts or conduct be used as evidence against him” (HAROLD V. TAMARGO vs. ROMULO AWINGAN, et al. G.R. No. 177727, January 19, 2010, Third Division, Corona, J.).
An exception to the res inter alios acta rule is an admission made by a conspirator under Section 30, Rule 130 of the Rules of Court:
“Admission by conspirator. — The act or declaration of a conspirator relating to the conspiracy and during its existence, may be given in evidence against the co-conspirator after the conspiracy is shown by evidence other than such act or declaration” (emphasis supplied).
This rule prescribes that the act or declaration of the conspirator relating to the conspiracy and during its existence may be given in evidence against co-conspirators provided that the conspiracy is shown by independent evidence aside from the extrajudicial confession. Thus, in order that the admission of a conspirator may be received against his or her co-conspirators, it is necessary that (a) the conspiracy be first proved by evidence other than the admission itself (b) the admission relates to the common object and (c) it has been made while the declarant was engaged in carrying out the conspiracy. Otherwise, it cannot be used against the alleged co-conspirators without violating their constitutional right to be confronted with the witnesses against them and to cross-examine them.
In Harold Tamargo vs. Romulo Awingan, et. al., aside from the extrajudicial confession, which was later on recanted, no other piece of evidence was presented to prove the alleged conspiracy. There was no other prosecution evidence, direct or circumstantial, which the extrajudicial confession could corroborate. Therefore, the recanted confession, which was the sole evidence against respondents, had no probative value and was inadmissible as evidence against them (HAROLD V. TAMARGO vs. ROMULO AWINGAN, et al. G.R. No. 177727, January 19, 2010, Third Division, Corona, J.).