Admissible evidence

In the law of evidence, the rule of thumb is that the information presented to the court should be as follows:
 relevant to the case; and
 admissible.

Hence, the interesting question is the meaning of admissibility. In a nutshell, it means that it is okay to present those information to the court as they were gathered reliably, and those information do not have unfair consequences to the defendent. 

The "hearsay rule" is one of the common exceptions.https://clic.org.hk/en/topics/Evidence/trial_stage/admissible_evidence It is not okay for another person to have heard it before, and then repeat it to the judge or jury. The person who said it needs to be willing to testify in court as a witness.https://www.hkreform.gov.hk/en/publications/rhearsay.htm

A further exception to the above "hearsay rule" is dying declaration in criminal cases. If someone said something relevant and then died very soon, what he or she said should be admissible. It is because, the now dead person might be the only possible witness in the world at that time.

Related page
Interrogation
Cross-examination

References

Category:law