corpus delicti
Meaning. The body of the offence: the facts showing that a crime has actually been committed.
Before anyone can be convicted, the prosecution must prove that the offence itself took place, for example that a person died and that the death was caused by an unlawful act. Proving who did it comes after that. The phrase does not mean the dead body, though in murder cases the two are often confused.
Failure to recover the body is not fatal to a murder prosecution. A conviction can rest on other evidence if the fact of death by unlawful means is proved beyond reasonable doubt, but courts treat such cases with great caution because the supposed victim may be alive.
Example
Though the body was never found, the blood-stained boat, the eyewitness to the struggle and the victim's sudden disappearance proved the corpus delicti.