I need to go back and watch past episodes to see if there are some gaps in logic, like the killer being somewhere and him being nowhere near where he needed to be to pull off a kill.
Yeah, I plan on rewatching both seasons. Knowing who the killer is, gives you a completely different view on the events. I do wonder how much he was involved with the killings of season 1, though, so I already did a quick viewing of some key events from season 1.
Some things I think he did:
- Check out Nina's house for entry points and such. Hence why he went home with her after they met at the bar the day before she got killed.
- Kill Rachel. Audrey said Piper was with her. So yeah.
- Attack Will (and Piper). Pretty obvious.
- Tie up (and probably kill) his dad. Piper was at the dance with Emma when the feed came on and wasn't gone long enough to be the killer to enter the screen. Kieran, however, left quite a bit beforehand.
- Free Branson from the police station, since he knew his way around.
- Capture Branson at Brooke's house and tie him up. The lights weren't off long enough for it to be a one-man job. Piper couldn't have knocked him out, dragged him out of sight, tied him up and then reappear before Brooke when the lights came back on.
Hope we got some clarity on his involvement!