According to Deadline, Edward James Olmos (Battlestar Galactica) has joined the 6th season of Dexter for a "major season-long arc", where he'll be playing a professor of religious studies. He is one of multiple new additions to the cast, including Colin Hanks and Mos Def.

This season's storyline will focus on the relationship between Dexter and his sister, and will not necessarily feature on a single main villain. If you missed our previous coverage, check out the Dexter Season 6 teaser trailer: http://dailydead.com/dexter-season-6-teaser-trailer-plot-info/

Source: Deadline