I just wanted to point out that if he is considered mentally unstable, they can pretty much lock him up for life. This crime exceeds any crime in Norway since Quisling, and I honestly doubt they're going to simply let him walk away after 21 years.

@JemyM
I agree, and for a long time the extreme right wing nationalists were considered the most dangerous even by the general crowd. That opinion seems to have changed recently (mainly due to muslim terrorists), but there might be another shift now because of Breivik.