Originally Posted by GhanBuriGhan 
That… Was very tasteless
Agreed.
As for the second arrest. It was a young man carrying a knife, and he allegedly screamed that he carried a knife. I would be surprised if he had anything to do with the shooting, but I don't think the police had any choice given the circumstances.
Edit: Regarding a possible accomplice: The police say this is solely based on some witnesses at Utøya. They're not actively looking for another perp.
Edit: I'd like to thank you all for your support. AFAIK my family and I are not personally affected, still, like many other Norwegians I'm devastated. So: Thank you.