He's a he, yes. This is going to be tricky with the name changes. His name is Belko Royce in the American version, and he and Stan Larsen (father of the murdered girl) have known each other most of their lives. Belko helps Stan with his moving company, and he's sort of a casual, unofficial member of Stan's family. Belko is only a fringe player in the story we've been shown so far, never a director of the action but more a follower. That's what made me suspicious. There's an old trick in TV crime shows: the killer is introduced early in some innocent situation and then drops out of the action. Then he's brought back again, to remind the audience that there is such a character in the story. This may happen again, depending on the length of the show. So at the end, when he's revealed as the killer, the audience can't say "Who's this guy, where did he come from?" L&O's various episodes use the device all the time; so does NCIS, and probably other crime shows that I don't watch. But that's exactly the way The Killing has been showing Belko, in an insignificant sort of sidekick role.
There are internal pointers to Belko as well. He and Stan may have shared a criminal past. The police learn that the murdered girl's body was moved in a car that belonged to the campaign staff of a local politician running for mayor, and for a while the spotlight is on the politician. Belko offers to "take care" of the politician for Stan, but Stan says no, because "I don't do that any more." They've both killed in the past? Sounds like it.
The police believe the campaign car was stolen and turn their focus elsewhere. Belko finds out from a contact that the police do have a suspect, and he's one of the murdered girl's high shool teachers. So Stan and Belko grab the teacher and take him to an isolated spot, where Stan proceeds to beat the crap out of him. When Stan's finished, Belko steps in and starts kicking the man while he's down. He kicks the teacher so viciously that Stan has to stop him from killing him.
Belko isn't on the screen very much, just enough to establish two things: he's violent, and he's in and out of Stan's home a lot. That's adequate preparation to reveal him as the killer. It's understandable that the American version would want a different killer, but leaving those pointers to Belko in the script instead of turning them toward someone else -- that's just a red herring, always a cheat.
So, Andrew, is there a Belko-like character in the Danish series? And is he the killer?