Christopher? Must be Norwegian.
An interesting blog comment:
The mainstream media has worked very hard to censor his name from the reports -- some give his full medical history (mental illness and hospital stay due to mental illness), his father's street address, and then add "the name of the gunman is not known" Well, duh! How do you get someone's detailed mental health records without knowing their name? His surname is not supportive of the agenda.
ZabaSearch finds exactly two people in the US named Zawahiri (same as the AQ chief). However, it finds 24 (including the late father of the shooter) named Zawahri, which is how it is pronounced in Egyptian Arabic, according to the Wikipedia.