"Plenty of opportunity for the resident muslims to plant literature if they wanted."
I'm not following you with this. A student straps a bomb to himself and heads out in the direction of a stadium filled with 80,000 or so people, and dies when the bomb detonates just outside the stadium. But, any Muslim "literature" could have been planted by Muslims on the hall of his dorm?
They must be using technology that triggers any electrical charge within a specific perimeter.
Would be nice if it were true.
That's speculation. What is known is a bomb exploded and a student is dead. A bus driver saw him sitting on a bench before something went BOOM. A female witness saw two middle-eastern running away toward the stadium immediately after the explosion.
If he was sitting on the bench as reported, someone could have left the bomb on the bench either before he sat down or after, then departed. The sweeps with bomb-sniffing dogs prior to the explosion could have foiled any plans (by whomever) to take the bomb(s) into more densly packed area. There apparently was concern earlier that additional security and sweeps were necessary. Whoever was walking around with a backpack of explosives would have sought other methods for placing it, or getting rid of it.
My speculation makes just as much sense (to me at least) as any that has been reported. Reports from the investigators, media, and university president are in conflict with someone who knew the victim better than any of the former. So everyone will have to make their own choice about who to believe.