The 7th Earl of Lucan, who disappeared in November 1974 after leaving the nanny of his children dead in a sack, and his wife brutalised. Although it is unclear what became of him after the warrant for his arrest was issued, many people claim to have seen him around the world since, and the British Tabloids
will occasionly run a story on someone who may be him.
Full story at LordLucan.com
He has been missing long enough for his peerage to be given to his son.
I saw Lord Lucan on my trip to New York.