Since the article didn’t say, that is a distinct possibility.
From regional reporting....the guy (Iranian) has been on a watch list since 2015. He has multiple entries for drug-trafficking (his primary occupation) and assault. Far as I can tell...doesn’t appear that he ever spent more than a couple of weeks in jail for any offense.
Key thing, his mother said it clearly....for more than a decade, the guy has been a paranoid schizophrenic....self-medicating more or less.
He’ll be classified as a nutcase, and sent off to a facililty...no charges, I think will be supported in court.
If the Norwegian cops there were to open up all criminal records and review people for schizophrenia, there would be a minimum of 500 people who ought to be locked up.