The fairly new to town author-turned-professor Richard Ryan (played by Guy Pearce) has been pretty unproblematic till now. Apart from being a smooth-talking, promising romantic interest for Mare, he hasn't been hinted to be linked with any of the criminal affairs of the town. But could it be that he befriended Mare just to gain her trust and be in the loop about the ongoing investigation to steer clear of any roadblocks in his way? It's always the charming ones that turn out to be complete sociopaths, I tell you! Mindy Kaling seems to think so.
Another interesting fan theory postulates that, if true, this could be Richard's way to break free of the writer's block he's experiencing and create a storyline for his future novel himself. It may be far-fetched, but I'm sold on this idea.
A Reddit user even picked up on a clue in the preview that backs this theory. Tell me the guy in this screenshot doesn't look like Richard? I have my eyes on him, is all I'm saying.