The recently released list of most-wanted terrorists includes terrorists going back to 1985, with the hijacking of the TWA flight. I have seen reports that Imad Mugniyeh was also associated with the bombing of the Marine barracks in Beirut in 1983. (see here for example http://www.jpost.com/Editions/2001/10/11/News/News.36005.html )
But that crime was not mentioned on the FBI site. I looked around the web a bit, and couldn’t find any mention of attempts to bring the terrorists behind that act to justice. I was a bit young then, but I imagine there must have been tremendous outrage at that act. Were any of the terrorists placed on the wanted list then? Have any been apprehended or killed? Most of what I have found has dealt with which states had responsibility – Syria, Iran, etc.