This sounds very much like a person that I worked with in Taif, Saudi Arabia in 1995-6. I will try to be as pleasant as possible, but if about this time, he was a white male, in his mid-late 40's, balding, with a growing paunch, then that's the guy.
This is the one person (amongst a few runners-up) that I swore I would never work with again. It was obvious that he was a hurting individual as he made EVERYONE want to be in a different room whenever he walked through the door.
If we're talking about the probably same guy...he had walked VERY FAR away from your religion as I admire Mormon's sober lifestyle. I won't mention what Don was engaged in when I knew him, but your worst fears are probably spot on. As I said, he was a person who was clearly hurting and I theorized that only by spreading his pain to those he worked around was his only solice. At the time I had to endure him, he claimed to have been a Captain in the U.S. Air Force...something I doubted as I also served and he had no marking of the bearing of an officer.
If the F.B.I. is interested in trying to find his whereabouts or known addresses, they can try by contacting Raytheon International Services Company (RISCO). This is the overseas hiring wing of Raytheon Defense Systems. He attempted to get them to hire him in 2002.
The next time Don and I crossed paths was at the 2005 TESOLArabia Conference in Dubai. I did my best to make myself scarce around him as I didn't want to find out that he'd forgotten how badly he treated me in Taif and walk over to chit-chat.
These are my latest contacts and sightings of this particular "Don Viner". I believe that we are talking about one and the same person. He did mention that he had kids and had a divorce from his wife. His lifestyle indicated that he had a very strong dislike of women.
Again, I hope that this message hasn't hurt you in any way, but I thought that, if he resenbled the person that I described, then, maybe, the F.B.I. could update their files.