The top right Vévé in the initial shot of the Nigerian drug lord's lair is that of Maman Brigitte, a loa only worshipped in Haitian vodou (and some rather syncretistic versions of Catholicism). Since it has been stated earlier in this episode that the vodou ceremonies shown were "hardcore Nigerian", it would be more than unlikely to find someone adhering to the Nigerian branch of the religion using the symbol of a loa from Haitian vodou.
The captain says the lawyer of the first victim is killed the very same day so there must be a connection, but at that point they did not have the identity of the victim, so they could not know who his lawyer was.