Why it was necessary to capture Osama dead

The US has avoided a lot of extremist attacks by capturing Osama dead. Had America captured the Al Qaeda chief alive, there would have been a series of very violent attacks on the US interest in the world. These attacks would be more focussed on plane hijackings, hostage taking and massive bombings near the US embassies in the world. The current anger over the death of Osama would have multiplied manifolds in case of his arrest.