Kensei photo wasn't among the group, so it is likely matt's father that is the boogeyman and the killer

Matt's father doesn't fit the build of the person who took out Kaito. Unless he worked out, lost weight, and got shorter. There is always the possibility that Matt's father has some ability like Candice, however that's unlikely.

there was one more person in the photo on the bottom right, who nathans hand was blocking... he looked like he was croutching down, possibly could be kensei/kane, but who knows.. it was such a quick shot..

check out the '12' post... there are some photos there..

I think they pretty much established that parkman's father was the boogey man just by molly's reaction and the fact that he "saw" her and "captured" her when she found him.

In the "12" post, the second photo has a good shot of the man in the lower right corner...I'm not sold on the fact that he is kensei but anything's possible I guess. I'm more interested to know why Mr. Petrelli is looking behind Angela in that photo...why wasn't the photo taken over again? What was he looking at...no one else to his left is looking at him.

And as far as who's killing them off...my theory is that it's a future peter that has come back to get rid of them.