But "how the terror is being caused" is vital. Al Quada likes to use suicide bombers, etc., because a suicidal person is very malleable, and the successful suicide bombing leaves behind no witnesses who could testify against the funders and organizers of the terror. There is a definite profile and MO that an al Quada bomber fits, and this shooter doesn't fit it.
Also - although Palestinians have used gunmen and shooters in their jihad against Israel, they take credit for it. "Causing terror" isn't enough - the islamos want people to know WHY they are terrified.
It could be a "lone muslim nut", but this guy is not connected to al Quada.