Spying and gathering intelligence overseas often require deception. In contrast, testifying under oath in federal court requires telling the truth, the whole truth, and nothing but the truth.
But sometimes there are exceptions.
This week at the federal trial of suspected Al Qaeda recruit Jose Padilla, a covert agent of the Central Intelligence Agency took the witness stand. He told the jury his name was Tom Langston, but it isn't. And no one informed the jury that he was testifying under a pseudonym.
In addition, it appears that Mr. Padilla's lawyers don't know the key witness's real name at the CIA's request.
Withholding information from a defendant and his counsel at trial is unusual in American courts, although not unprecedented. But it could raise a potential issue for appellate court judges to decide whether Padilla's Sixth Amendment right to confront witnesses against him has been violated.
To some legal analysts, the episode highlights a danger that the criminal justice system is straining to accommodate the Bush administration's war on terror in ways that threaten to undermine traditional civil liberties.
But others say it appears that US District Judge Marcia Cooke, a Bush nominee confirmed in 2004, is making a conscientious effort to balance fair-trial protections against the potential national-security implications of the Padilla trial.
Although the CIA agent has testified in open court this week, it is difficult for the public and the press to understand the full context of the courtroom encounter. Rulings on the subject by Judge Cooke are under seal in the secret portion of the Padilla trial docket.
But the agent's appearance in court closely tracks a series of CIA requests to the judge. Because the true identity of the agent is classified as "secret," CIA officials asked that he be able to testify using an alias, wearing a "light disguise," and that he be permitted to enter the courtroom through a secure nonpublic entrance. In addition, the CIA asked that the agent's real name not be disclosed to the defendants or defense counsel.
"Allowing [the CIA agent] to use a pseudonym is pretty uncontroversial, especially if it is someone who is an undercover agent," says Robert Chesney, a national-security law specialist and professor at Wake Forest School of Law. "The harder question is why is it OK for the defendants to be limited in their ability to impeach [the CIA agent's] credibility because they don't really know who the guy is."
Witness names withheld before
In a public filing to the judge, prosecutors cited a series of cases withholding a witness's true name. Some involved Mafia trials and individuals in the witness-protection program. Others involved intelligence agents.
In one case, a US marine was convicted of passing classified information to a Soviet agent. A US intelligence agent testified under a pseudonym and his real name was never disclosed to the defense. That case was a court-martial rather than a jury trial in federal court.
Last year, for a pretrial hearing, two Israeli agents were permitted to testify using pseudonyms. And in 2005, Saudi intelligence officers offered videoconferenced testimony under pseudonyms, also in a pretrial hearing.
In 2004, a federal judge in Illinois permitted a former Iraqi intelligence officer to testify in a federal court trial using an assumed name.
"It seems the government is getting pretty much all they asked for," says Carl Tobias, a professor at the University of Richmond School of Law.
In the Padilla case, the CIA agent's testimony is important because it relates to a key piece of evidence: a five-page "Mujahideen Data Form" Padilla allegedly filled out before he reportedly attended an Al Qaeda training camp in Afghanistan.
"The fact that this form even exists proves that Padilla was there," Assistant US Attorney Brian Frazier told the jury in his opening statement on Monday. "Al Qaeda kept files on everything."
But the government faces a challenge in establishing the authenticity of the data form. That's where the CIA agent's testimony is crucial.
The agent is the first US government official to take possession of a large volume of documents said to have included the Padilla data form. The agent told the jury that in December 2001 an Afghan drove a twin-cab pickup truck loaded with documents to a covert CIA office in Afghanistan. The Afghan told the agent that he'd recovered the documents from an office abandoned by "Arabs" in Kandahar after the US invasion.
The agent, who said he could neither read nor speak Arabic, testified that he examined the documents and then locked them in a secure room before sending them to the Federal Bureau of Investigation for analysis. It wasn't until the documents were translated from Arabic to English in the US that officials discovered the alleged Padilla data form.
The agent's testimony does not establish the origin of the data forms, only how the government says it first obtained the documents. The agent's testimony about how the documents got into the Afghan's pickup truck is hearsay – based entirely on the statements of the Afghan. Such evidence is usually inadmissible as proof in a trial. However, in a trial involving classified information, the judge is empowered to admit evidence that otherwise might not be admissible.
One way to establish the origin of the Mujahideen Data Form would be with testimony from the unidentified Afghan with the pickup truck. But his name and the name of his tribal leader appeared to be off-limits to Padilla defense attorney Orlando do Campo during his cross-examination of the CIA agent.
Legal analysts say it is probable that the scope of Mr. do Campo's cross-examination was sharply limited by Judge Cooke in earlier closed-door hearings designed to prevent defense attorneys from asking questions that might touch on classified intelligence sources and methods.
Under the Classified Information Procedures Act, it is up to a judge to decide how best to balance the need to protect national-security secrets in the context of a fair trial.
During his cross-examination, do Campo asked about the possible motives of the unidentified Afghan who delivered the documents to the CIA. The agent responded: "I have a difficult time speaking to their motives."
Fingerprints on the data form
In earlier court filings, defense lawyers have suggested that the Padilla data form may have been filled out by someone other than Padilla, using two different kinds of ink typically not found outside North America.
Federal prosecutors say that tests found Padilla's fingerprints on the form, proving that he filled it out. But defense lawyers counter that his fingerprints were found only on the first and last page of the five-page document. They say the tests show no palm edges or other indications that Padilla actually filled out the form. And there are many other fingerprints on the pages, they say.
"The fingerprint evidence is far more consistent with Mr. Padilla being shown the form during his three years and eight months of interrogation in [the military brig in] South Carolina than with having completed the form," writes Michael Caruso, another of Padilla's lawyers, in a motion to the court filed last month.
Mr. Caruso urged the judge to permit the defense "considerable leeway" to investigate the chain of custody of the data form and that the defense be permitted to engage in vigorous cross-examination. That motion appears to have been denied.