The case *may* be dropped--it depends on whether the prosecutor feels that there is enough evidence or testimony to convict without the testimony of the deceased. A criminal case is not like a civil case: the victim of the crime is not in control of a criminal case, the way someone injured in, say, a car accident is in control of his or her lawsuit and is the one bringing the lawsuit. Rather, the victim is essentially a witness to the crime. His or her testimony is obviously very valuable, but it is not necessary if there is enough other evidence or testimony (e.g. from other witnesses)--or even a confession or incriminating statements from the accused--that the case can be proven. So if the prosecutor feels that he can proceed without the deceased, he may; but if he feels that the deceased's testimony was necessary, he is likely to dismiss rather than pursuing a losing case.