Washington lawmakers were demanding Monday to know why and how the FBI failed to disclose documents and evidence in the Oklahoma City bombing case during the trial three years ago. The revelation has prompted bomber Timothy McVeigh to reconsider not appealing his execution. 

Members of Congress are asking for hearings into how the FBI failed to turn over 3,000 documents to the defense, and one Democrat wants President Bush to appoint a blue-ribbon commission to review the FBI. 

McVeigh was to be executed Wednesday for the April 19, 1995, bombing of the Alfred P. Murrah Federal Building in Oklahoma City that killed 168 people, including 19 children, a crime to which he has confessed. But just last week his defense team was handed 3,135 documents and pieces of evidence — including interview reports and physical evidence such as photographs, letters and tapes — which had been withheld from his lawyers during the original trial. 

Attorney General John Ashcroft postponed McVeigh's execution to June 11 in light of the FBI lapse, and now McVeigh, who had decided not to pursue further appeals of his execution, has said he is rethinking that position. 

When McVeigh originally decided not to pursue further appeals, he had no idea the FBI had withheld evidence, attorney Robert Nigh said Sunday. 

"In light of that, it's completely reasonable for him to re-evaluate his position," Nigh told Fox News Sunday. "The facts of the case are now certainly at issue." 

McVeigh "has indicated now that he is at least willing to take a fresh look at things, hear our analysis of the facts contained within the documents and our legal analysis of his options," Nigh said on CBS' Face the Nation. 

Defense attorney Nathan Chambers questioned whether the FBI has disclosed all evidence. "Are we going to learn next week that there are yet more documents?" Chambers said on ABC's This Week. 

"There are a lot of questions that a lot of people have for the FBI, and as we move forward in these next few days, that question will be one that is answered," said Mindy Tucker, spokeswoman for Attorney General John Ashcroft. 

Beth Wilkinson, a former prosecutor in the case, said she believed the foul-up was unintentional and that the documents should not affect the outcome of the case. 

"He has confessed to the crime. The evidence during the trial was absolutely overwhelming," Wilkinson said on ABC. "I believe it is very unlikely that there will be any information that would be useful to Mr. McVeigh." 

Ashcroft said he will not impose any further delays. 

The defense team has just begun reviewing the documents and Nigh said he was not prepared to disclose what was in them. He did, however, contend that "the fact of the production itself could possibly change the legal outcome of the case." 

McVeigh, who is in a federal penitentiary in Terre Haute, Ind., had indicated he "did not wish to spend the rest of his life in an 8-by-12 cell," Nigh said. But that was after losing court appeals, and before the new evidence now available to him, the lawyer said. 

Asked about trying to put off the execution beyond June 11, Nigh said: "It is his case, and he has to determine what he wants to do." 

Sen. Charles Schumer, D-N.Y., said he would ask Bush for a special commission to examine the FBI from top to bottom. 

Schumer cited a number of problems at the FBI, including the February arrest of agent Robert Philip Hanssen, who is charged with selling national secrets to Moscow, and a botched investigation last year of former nuclear scientist Wen Ho Lee. 

"We've had mistake after mistake after mistake," he said on CBS. 

Ashcroft already has announced a separate Justice Department investigation. 

Bush said last week he awaited the findings of two investigations into FBI procedures — Ashcroft's and an earlier one ordered after the Hanssen charges. A White House spokeswoman pointed to those investigations when asked about Schumer's request. 

Sen. Charles Grassley, R-Iowa, criticized the FBI and its director, Louis Freeh, who recently announced he will retire in June. 

"I think there is a management culture here that is at fault. I call it a cowboy culture. It is kind of a culture that puts image — public relations and headlines — ahead of the fundamentals," he told ABC. "I don't think he [Freeh] has been willing to challenge the management culture." 

Congress must approve Freeh's eventual successor, and several lawmakers said they hope President Bush will choose someone who can reform the agency.