One of the 16 people sought for questioning in an alleged terror plot in Boston has been in federal custody for more than two months and has no terrorist connection, the FBI said Saturday.
In an announcement posted on the FBI Internet site, officials said that Mei Xia Dong, a Chinese woman, has been at a Homeland Security Department immigration detention facility in San Diego since Nov. 11.
The match was made soon after her name surfaced last week as part of an anonymous tip about the possible terror plot. The original information indicated that Dong was a 21-year-old man.
Investigators say Dong paid a human smuggler to enter the United States through Mexico and that she came to this country only for economic reasons.
Authorities are continuing to search for 12 other Chinese, two unnamed Iraqis and one Hispanic man who may have been part of the same group. But no evidence of terror motives has surfaced, as the tipster claimed.
"We're going to investigate it to its logical conclusion, but to date there's no corroboration of the original claim," FBI spokesman Joe Parris said.
One leading theory in the case is that the motive for the tip came from the smuggler to exact revenge on the group, perhaps because members failed to pay. Officials have stressed since news of the tip first broke on Wednesday that they doubted the credibility of the terror claims.
Probe grows, concern wanes
The agency announced Wednesday that it was investigating four Chinese nationals, and a Transportation Security Administration official said later that a security briefing indicated the FBI also was looking for two Iraqis. The number jumped by 10 Thursday “as a result of the ongoing investigation,” but that did not signal that credible evidence about a plot had emerged, FBI spokesman Joe Parris said.
“Information is still uncorroborated and from a source of unknown reliability and motive,” Parris said.
Another federal law enforcement official in Washington, speaking on condition of anonymity because of the ongoing investigation, said the tip was received by the California Highway Patrol. The tipster claimed the four Chinese — two men and two women — entered the United States from Mexico and were awaiting a shipment of “nuclear oxide” that would follow them to Boston.
Several radioactive compounds take form as oxides and could be used in a dirty bomb, expert Charles Ferguson said. Plutonium and americium oxides, in the right amounts, would be dangerous to human health, while uranium oxide would be less so, he said.
“They vary in potency,” said Ferguson, science and technology fellow at the Council on Foreign Relations in Washington. “If it was plutonium, we could have a problem on our hands.”
Gov. Mitt Romney said Friday that he has become “less concerned, not more concerned” about the threat since it was first reported Wednesday.