I'm not sure there's anything wrong with Stalker. After the first few episodes it is settling down into what it can become. I think the problem is that what it is becoming isn't really anything special. Stalking crimes can be pretty unpleasant and while the rest of the cast around that premise isn't bad, they don't rise to the exceptional level needed to overcome the core unpleasantness. So at this point I would not be surprised if they didn't get renewed for next year.