The White House said Thursday that two federal air marshals appeared to have acted properly when they shot and killed an agitated passenger who claimed to have a bomb in his backpack. No bomb was found, and authorities later said Rigoberto Alpizar, the passenger killed Wednesday at the Miami airport, was not a terrorist. Witnesses said his wife had frantically tried to explain that he was mentally ill and had not taken his medication. "I don't think anyone wants to see it come to a situation like this," White House spokesman Scott McClellan said. "But these marshals appear to have acted in a way that's consistent with the extensive training that they have received. And we'll see what the investigation shows, and lessons learned from that will be applied to future training and protocol."