I have heard of murder case that have resulted in a Guilty verdit when the body was never found!!!!!!!
If you mean "NEVER HEARD," consider the case of Irene Silverman, who was murdered by the wacky mother-son incestuous duo in an attempt to take over her Manhattan townhouse. The body was never (even) recovered. They were both convicted.
Later the son confessed that he dumped Mrs. Silverman in a construction site in New Jersey.