An FBI negotiator was on the second floor of the house looking down at the boat, but he couldn't see Tsarnaev under the tarp.

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"This was a classic, textbook situation, " said Clint Van Zandt, a former FBI negotiator who worked with the hostage rescue team repeatedly before retiring in 1995.

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"You are dealing with a business--they have decision makers, a negotiation team, an implementation team, " says Christopher Voss, who last year retired as the FBI's chief international kidnapping negotiator.

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