I hate the detective side story
Ugh..I hate it. I liked that he was an undercover cop..that was a cool twist, but now it's pointless. I literally don't give two craps if he finds his daughter. The only way I'd change my mind is if it turned out his daughter was the killer. That would be another good twist, but since I've read the spoilers I know that's not true, so why even have that story line? There's waaaay too much drama already this season, they don't need another useless storyline unless it had to do with Kate's death somehow. I find his character completely unlikeable as well.
On a positive side, I like seeing Brendan Hines on TV again. I loved him on Lie To Me. I really like his character on this show too. I like that he has Cornell's back, she needs a friend. Her having a partner is a nice addition. I like Cornell and I like that we're getting to see more of her personal life. No one is shut off like her without reason. I don't mind her side stories because she's the only constant character so far, so i like finding out how she ticks. The detective story line has no purpose. I highly doubt he'd be back next season, if there was one.