Spontaneous declarations, made simultaneously with a transaction or occurrence, and expressive of its character, motive, object, or cause, are regarded as res gestae and admissible in evidence along with the main facts of the transaction or occurrence, and as a part thereof, and explanatory of its nature.

In criminal cases, statements made at the time of the commission of the offense by the accused are generally admissible to prove the intent, when not self-serving. This is especially true in the law of conspiracy. The unlawful combination and the common design having been established by evidence sufficient in the mind of the court, each and every act or declaration of each of the conspirators in furtherance of the common design becomes admissible against each and all of the conspirators, the act of each being the act of all.

When such declarations consist of questions and answers, statements and exclamations, occurring shortly after the transaction or occurrence, the problem becomes hopelessly involved. And where such declarations become narrative of a past transaction, or sufficient time has elapsed in which to plan and utter false and misleading statements, they are not allowed by courts to be introduced in evidence. They must occur contemporaneously with the main facts of the transaction or event. Involuntary exclamations of pain so closely associated with the accident as to be a part of the res have been received in evidence.

3 1 Greenleaf, Sees. 128-130.