We don't know if it matches. We don't know why he did it, why he stopped, or why he told the cops about the IEDs in his apartment. But here's the thing. We don't really need to know at this point.
Maybe there are other things playing out. There are almost certainly undisclosed elements. This whole "the people have a right to know" attitude that permeates everything these days needs to stop. Sometimes making too much information public is counter-productive and even dangerous.
Also, it's not the first large scale shooting where the shooter was taken alive. Look at Brevik in Oslo.
This man now has the attention of the entire country in order to make his point.