According to this article on CNN.com, the suspected person was an applicant for landed immigrant status. One would have assumed that the government has already thoroughly investigated his background as part of the application process.

http://www.cnn.com/2005/TRAVEL/05/19....ap/index.html
"Homeland Security officials said the man, whose name was not made public, was not a suspected terrorist. After questioning, he voluntarily withdrew his application for status as a permanent legal resident and will be deported, Customs and Border Protection Assistant Commissioner Kristi Clemens said Wednesday."

I can't say I'm surprised he decided to withdraw his application. I would as well.