Board Thread:Questions and Answers/@comment-24.4.122.254-20130629204233/@comment-70.209.9.12-20130819111528

I am almost positive the brain surgeon is Cassie's boyfriend. If you remember the conversation Debra had with Cassie, Cassie revealed that she was pining over Dexter despite dating the other, "normal" guy. Also, there was a scene where he saw Zach with Dexter, when he and Cassie were going for a midnight swim. Well, when he met with Quinn after Cassie's death, he lied about both of these facts. He knew exactly where he had seen Zach and he told Quinn that he and Cassie had been discussing a future together, something that doesn't jive with what Cassie told Deb. These facts, plus the amount of screen time this character has gotten, leads me to believe he's our killer.

However, I expect there to be a connection between him and Vogel that she hasn't told us. Perhaps a son?