U.S. can't locate two with known or suspected terror ties By Jake Tapper, CNN Chief Washington Correspondent May 16, 2013 -- Updated 1656 GMT (0056 HKT) FIRST ON CNN: Two were former participants in federal witness security program They were identified as being known or suspected terrorists Details emerge from interim Justice Dept. inspector general's report Washington (CNN) -- The U.S. Marshals Service has been "unable to locate" two former participants in the federal Witness Security Program "identified as known or suspected terrorists," according to an interim Justice Department inspector general's report obtained by CNN. The marshals have concluded that "one individual was and the other individual was believed to be residing outside of the United States." The news comes from an audit of the Witness Security Program by the inspector general's office, which states that "the department did not definitively know how many known or suspected terrorists were admitted into the WITSEC program," among other "significant issues concerning national security." The report makes 16 recommendations. The Marshals Service referred calls to the Justice Department, which said in a statement that the number of former known or suspected terrorists ever in the witness program "represents a fraction of 1 percent" of its total participants. "To date, the FBI has not identified a national security threat tied to the participation of terrorism-linked witnesses," the Justice Department said. The news comes amid a difficult week for the Obama administration following revelations of IRS targeting of political groups, more fallout from the deadly attack on the U.S. mission in Benghazi, Libya, last year, and news that the Justice Department secretly collected phone records of journalists as part of a leak investigation.