WASHINGTON -- The Supreme Court chose yesterday to stay out of the Iran-contra scandal, leaving a special prosecutor the option of going back to a lower court for a possibly futile attempt to salvage the convictions of former White House aide Oliver L. North.
Without comment, the court turned aside an appeal by independent counsel Lawrence E. Walsh, who was attempting to revive two convictions of Mr. North that had been set aside by a federal appeals court last July.
The Supreme Court similarly turned down a separate appeal by Mr. North seeking to bar any new trial on those two charges or on a third on which he also had been convicted. A jury found Mr. North guilty of three crimes in connection with his role in an alleged White House plot to cover up the affair. The scandal involved an attempted deal to free U.S. hostages in Iran and a secret war -- run from the White House -- against Nicaragua.
The court's refusal to get involved was a good omen for Mr. North's former White House boss, ex-National Security Adviser John M. Poindexter, who is seeking to take advantage of the appeals court ruling in Mr. North's favor in pursuing a pending appeal of his own conviction.
Although Mr. North's appeal to the Supreme Court failed yesterday, along with the prosecutor's, the justices' action amounted to a tentative but significant victory for Mr. North because the next legal stage may be so difficult for Mr. Walsh that the entire case could be scuttled.
Despite the likely difficulty, Mr. Walsh promptly announced that he would take the case back to U.S. District Court here. The next step there is to be a special and probably quite prolonged hearing on the constitutionality of the grand jury investigation and the trial of Mr. North.
The issue, to be explored with every one of the 89 grand jury witnesses as well as the 32 witnesses at Mr. North's trial, is whether any of their evidence was "tainted" by what they learned from the televised testimony Mr. North gave to Congress in 1987 under a promise of immunity for what he said.
Under a 1972 Supreme Court ruling, testimony given under immunity cannot be used in a later criminal prosecution. The appeals court said that that ruling could be satisfied in Mr. North's case only by a witness-by-witness, possibly line-by-line, review of all the evidence.
Mr. Walsh had told the Supreme Court in his appeal that such a proceeding "will require a complex psychological inquiry into the thought processes and memory of every witness."
Mr. North's chief lawyer, Brendan V. Sullivan Jr., told reporters in a statement he read at his office that the new "courtroom battle . . . will last for months and, if there are appeals following, could last for years."
The defense lawyer called the special prosecutor's plan to keep the case going "unwise and outrageous" and accused him of reneging on a promise not to do so.
Mr. Sullivan said that Mr. Walsh "told me directly in private meetings and in phone conversations that, win or lose in the Supreme Court . . . he was not going to drag Colonel North back through the District Court. He told me, in his words, he had 'no stomach for going back to the District Court.' Yet, that is exactly what he intends to do. He abuses the process by continuing further."
Mary Belcher, a spokeswoman for Mr. Walsh, said in reply: "There were discussions regarding the possibility of North's cooperation [in Mr. Walsh's continuing investigation], but these discussions never culminated in any agreement."
Mr. North, a retired Marine lieutenant colonel, was the first major player to be convicted in the scandal that tainted the administration of President Ronald Reagan.
The former aide was found guilty of illegally shredding secret White House papers to help conceal his role in the Iran-contra affair, of helping high-ranking officials try to keep Congress from learning the details of the scandal and of accepting an illegal gift from individuals he had helped to earn money from the scandal.
In its ruling last July, the U.S. Circuit Court of Appeals here threw out the most celebrated verdict against Mr. North -- on a charge of shredding and altering secret papers dealing with the scandal. That conviction was voided because of flaws in jury instructions.
The Court of Appeals also set aside the other two convictions because of the possibility of "taint" from Mr. North's immunized congressional testimony. If a District Court judge does find taint, it could nullify the entire case against Mr. North, or at least require a new trial.
If no taint is found, then the two convictions for aiding in the cover-up and accepting an illegal gift would be reinstated, but there still would have to be a new trial -- at Mr. Walsh's option -- on the document-shredding charge.