By Jessica Dye
NEW YORK (Reuters) - The trial of a man accused of obstructing an investigation into a plot to bomb New York City subways may not make clear to New Yorkers the details of what authorities say could have been a devastating attack.
Najibullah Zazi, 26, has been called as a defense witness in the trial for his father Mohammed, 55. The elder Zazi is charged with destroying evidence and obstructing a federal investigation into his son's plot to bomb the New York City subway system near the anniversary of the September 11 attacks.
The younger Zazi pleaded guilty in February 2010 to conspiring to use weapons of mass destruction and agreed to cooperate with the government. But his father is fighting obstruction of justice charges, which carry up to 20 years in prison. The trial opens on Monday in Brooklyn federal court.
But because of national security issues, the trial may not reveal everything New Yorkers might want to know about the case. That is because testimony from the son about the role his father played in covering up his plot could invoke classified information about his son's training with al Qaeda in the United States and Pakistan, legal experts said.
Such information could include the identities of undercover U.S. agents or the names of people central to ongoing investigation.
"The classic argument for why these cases need to be tried in military court is that the military courts have been better able to keep security matters out of the public domain," said Michael Greenberger, director of the Center for Health and Homeland Security at the University of Maryland Law School.
Prosecutors have already made use of the Classified Information Procedures Act, passed in 1980, which is designed to prevent defendants from threatening to reveal national security matters in open civilian court. And experts expect they will do so again during the trial.
CIPA allows government attorneys to present the judge with classified information during closed-door sessions. The judge then decides whether to block the information or ask lawyers to present an unclassified summary of it to jurors.
Federal prosecutors have cited CIPA several times in advance of the Zazi trial, arguing the defense's discovery requests triggered the law's protections.
Although details of the evidence and expected testimony are not publicly available, Najibullah Zazi has admitted to having traveled to Pakistan to train with al Qaeda, learning how to make explosives and pick targets as part of his plot.
"You can't control testimony in a live courtroom, but I'm sure it's being very carefully scripted," said William Snyder, who teaches national security law at Syracuse University.
The more vexing issue arises if prosecutors try to block testimony central to proving Mohammed Zazi's innocence, said American University law professor Stephen Vladeck.
If the classification and self-defense principles can't be reconciled, a mistrial could result, he said.
"The prosecution always has a remedy -- if push comes to shove, they can decide to declassify (it) if a piece of evidence is just too important to the case," Vladeck said.
(Reporting by Jessica Dye; Editing by Mark Egan and Eric Walsh)