Corpus Delicti

To try and convict someone of a crime that has not been committed means that there is no Corpus Delicti (Body of Crime).

 To prove that a crime has been committed, it needs to be proven that a crime has been committed in the first instance. This is primarily physical evidence, such as a murder weapon in the case of homicide, or crime scene damage to a property in the case of a burglary. This is probably why many rapists are not convicted. CCTV evidence can also prove that a crime has been committed in instances of rape and car theft for instance.

Therefore, proof that a crime has been committed is of primary concern when trying to serve justice.