This morning’s news had far more on an elderly man attacked by a “rabid motorist” than information on the Otoya mass murder. What little there is amounts to “we did the best we could, so we would do the same things today.”
As I read past police statements, Breivik had two firearms, and a substantial number of gasoline bombs. Of the two, the gasoline bombs had far more potential to kill, but Breivik was intent on shooting.
Otherwise, the Oslo and Norwegian police have remained silent. If I had to guess, the “green machine gun” Otoya witnesses report seeing was a 9mm. Possibly used in conjunction with the Glock 9mm registered to Breivik.
Why? Because frangible “perimeter defense” cartridges are generally tightly restricted to organizations that can demonstrate a need. Nuclear power plants, for example.
It would be much simpler to obtain a case of one caliber of such ammunition than a case each of two calibers. The Parabellum is the most common of the perimeter defense cartridges, so it simply makes sense that both of Breivik’s weapons would be the same caliber.
And all that about a Mini 14, drilling cartridges to fill with nicotine, and so on? Well, the Norwegian media seems to have looked hard enough, but the one Glock is all they can find registered to Breivik.