The article is not linked, but it says:
WASHINGTON (CNN) -- The United States has formally approached the bin Laden family and asked them for DNA samples, officials said Wednesday. The United States wants to rule out definitively that al Qaeda leader Osama bin Laden was not killed in a recent CIA missile strike in Zawar Kili in Afghanistan. The armed forces pathology lab is examining human remains from the strike. They are trying to determine the identities of people killed in the missile strike. One of the people killed in the strike has been described as tall, dressed in Arab white robes, and treated with deference by others, leading to speculation that it could have been bin Laden.
What can we learn from the decision to publicly ask instead of privately ask? Does it say anything about our suspicions?
If I DO THINK I'VE KILLED Osama, would I be more likely to ask publicly or privately?
If I think I've killed him, I'd definitely want it public. If I think I've not killed him, I'd definitely want it private. If I'm honestly uncertain, then there are propaganda purposes that could be served by either choice.
That the family has already been asked privately, and did not cooperate.
Does it say anything about our suspicions?
Certainly. We think we may have gotten him.
Going public also puts pressure on him to do something that shows he is still alive. When he does, and he must if he is still alive, he will give us clues.
That's probably all it means. You have to exclude as well as include.