Also, for all the commentary about a racial component, does this really sound like a terrorist target? Paris hit stadiums, concerts, the streets in general; public gathering places.
This was a school, technically, but it was a school for people with developmental or functional disabilities. And they hit a staff holiday party, not a class. The target selection says "personal motive". Maybe the justification was ideological, but the actual crime? That's a hard sell.
EDIT: Syed may have actually worked there. According to some sources, his coworkers identified him to first responders. That makes a purely opportunistic, terrorist agenda very unlikely.