General Discussion

The building in which the economics review session was being held is an Engineering and Physics building at Brown. Since the shooter appears to have targeted simply the first classroom he came across, there's no reason to believe he was targeting an economics class (or professor) and every reason to believe he was targeting engineers.

The professor at MIT was a professor of engineering and physics, specifically nuclear physics.

On Edit: Changed "in fact" to "apparently" in the title. I don't actually know whether the targeting was a fact!