Department of Homeland Security Secretary Janet Napolitano told ABC's Jake Tapper that authorities had not found any evidence that the bomb scare in New York City was part of a larger plot.

"We have no evidence right now that this is anything other than a one off," said Napolitano.

The federal government is treating the incident as a potential terrorist attack.

This video is from ABC's This Week, broadcast May 2, 2010.

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