The police would have interviewed Combs extensively.  If there were problems with his story they would have found them.  It is true that there are cases where the police feel sure they know who committed the crime but can't get enough evidence to bring charges.   This isn't one, for the simple reason that there's no evidence, at least known publicly, that any crime was committed. An unexplained disappearance is certainly reason for concern and investigation.  But since the police haven't felt able to take legal action, we have to assume that they simply didn't find anything to go on.  That's exactly what they say their situation is.  If they had anything that would even debatably hang it on Combs, the public would know it by now.  They clearly have no interest in him.