Jihad?
The photo sure does look like one to me too. Its very early though, so anything could really still be on the table.
Quite possible and that wouldn't surprise me. But not every act of violence is jihad. It well could be that, or it could be as simple as a nasty breakup. Time will tell.
In any event, it's horrible and tragic, and sympathies to the families, co-workers, and friends of the victims.
Prayer for everyone involved.