says the u.s. has banned political assassinations since the '70s, so it's not clear whether the killing was legal. the united nations high commissioner for human rights wants to know if the u.s. planned to capture, not just kill osama bin laden. so, the talk-back question does it matter if bin laden's killing was legal? facebook.com/car facebook.com/carolcnn. >> thank you. here's a look at what's ahead this hour on "the rundown." energy independence. another way to beat al qaeda? president obama talks clean energy to wean the u.s. off foreign oil. then dangerous flooding. the mississippi river forces thousands out of their homes. and april's job reports. economists pleasantly surprised. in addition to being the nation's 39th president, he played a mean game of softball. more of my exclusive