Marquin is now playing basketball in Bahrain. We just located an article in which he is mentioned very near the end as playing for the Al Ahli club. Here is the Facebook site for the team where a photo of Marquin can be found. Here is another mention of Marquin in an article that also notes he scored 43 points in one game.
Bahrain is an island country of approximately 800,000 inhabitants, located near the western shores of the Persian Gulf.