I do not believe that Norway will let this person go in 10 to 20 years. . .not multiply by 92 counts of murder!
What you believe has no bearing on what will ultimately happen.
Also, you are assuming that in Norway that each person's death will be a separate "count" as it is here in the U.S. Norway has its own system and it is much different (as are all countries), from the U.S. legal system.
It has been stated by those familiar with Norway's Legal system, that the perpetrator can only be imprisoned for a maximum of 21 years and has not death penalty...despite Steveox'es current blather on the subject.