Ahmed Ressam provided a piece of terrorism tradecraft — the construction of a paper detonator that could escape detection at airports — that may have saved the lives of agents investigating "shoe bomber" terrorist Richard Reid, his lawyers say.

This is just one example of a treasure-trove of intelligence that Ressam provided U.S. authorities piecing together the terrorism landscape after Sept. 11, the lawyers said yesterday in asking that Ressam be given a 12 ½ year sentence for planning to detonate a powerful luggage bomb at Los Angeles International Airport during the Millennium celebrations.

But a federal prosecutor last night said Ressam stopped cooperating with federal authorities in early 2003, breaching an agreement with the government. First Assistant U.S. Attorney Mark Bartlett said the government will ask that Ressam be sentenced to more than 27 years, which the parties had agreed to in 2001.

Ressam's "decision to stop cooperating has placed two significant, national-interest terrorism prosecutions in jeopardy," Bartlett said. He declined to name the cases, saying that information would be outlined in the government's sentencing memorandum, to be filed today.

Ressam will be sentenced here on April 27, more than five years after being arrested on Dec. 14, 1999, coming into Port Angeles from Canada with a trunkload of bomb-making materials.

In documents filed yesterday in U.S. District Court in Seattle, Ressam's defense attorneys said that he has proven to be one of the most significant resources in the war on terror, providing information that led to arrests of would-be terrorists in the U.S., Canada, Italy, Germany and France. "Planned terrorist attacks in Europe were prevented and individuals arrested," the documents said.

"Never has any individual provided information as important as that provided by Mr. Ressam," wrote federal public defenders Thomas Hillier, Mike Filipovic and Jo Ann Oliver. "And never has courage and risk of life been so evident."

They pointed to the case of Richard Reid, the would-be al-Qaida shoe bomber, as an example.

In a summer 2001 debriefing, Ressam told FBI agent Greg Carl how terrorists constructed a paper detonator designed to elude airport metal detectors. That December, the agent, an explosives expert at the FBI's laboratory in Quantico, Va., was called to Boston after suspected "shoe bomber" Richard Reid was arrested after trying to light a fuse attached to an explosive hidden inside his sneakers.

Agents at the Boston airport had X-rayed Reid's shoes and decided they were not dangerous because no metal blasting caps or detonators were detected.

"Agent Carl recognized a detonator of a type previously described by Mr. Ressam still attached to the explosive and he intervened," the pleading said, saving other agents from accidentally being killed or maimed.

The memo said prosecutors offered Ressam a 25-year sentence, with no requirement that he cooperate, if he pleaded guilty before trial. That had not been disclosed before.

His lawyers now argue that Ressam, "having renounced terrorism, having saved lives, and having provided priceless intelligence to our government and other governments," is entitled to the 12-year sentence despite the previous agreement.

In a letter to U.S. District Judge John Coughenour, Ressam wrote in early 2003 that "I am now firmly against such operations as I planned in America.... I believe that my participation in this operation has contributed to the negative perception of Muslims. I deeply regret this."

The lawyers' sentencing memo refers to a "breathtaking list of individuals Mr. Ressam identified and speaks to his courage and candor," but that list and details are under seal.

He first confirmed for U.S. authorities that the terrorist training camps in Afghanistan were not solely controlled by Osama bin Laden but involved leaders of other terrorist groups, the lawyers wrote. Ressam, trained in bin Laden's Afghan terrorist camps, was convicted in April 2001 of conspiring to commit an act of international terrorism and eight other terrorism-related counts and faced up to 130 years in prison.

Afterward, he agreed to cooperate with the government in its investigation into bin Laden and al-Qaida in exchange for a minimum 27-year prison term.

His status as an informer changed radically after the Sept. 11 attacks. Almost overnight, Ressam went from a would-be terrorist informing on members of a relatively unknown group to the first bin Laden-trained terrorist to offer an inside view on the network's methods, hierarchy, locations of cells and use of forged documents to cross borders.

According to defense documents, the 37-year-old Ressam has identified or provided information on more than 100 people.

They included Abu Zubaydah, the No. 3 man in al-Qaida whom Ressam stayed with for several week in Pakistan. Ressam carried Zubaydah's phone number with him when he was arrested.

Ressam was the key witness in the New York trial and conviction of Mohktar Haouari, the Montreal businessman who helped finance Ressam's failed airport attack. At that trial, in July 2001, Ressam detailed for the first time the training at bin Laden's camps, including the revelation that al-Qaida was experimenting with chemical weapons.

Information from Ressam also led to the indictment of Abu Doha, the man who ran the Algerian sector of the Afghan camps and who once met with bin Laden to offer his trainees, including Ressam, for al-Qaida's Jihad against the West.

Ressam's testimony was also central to the conviction in Germany of Mournir El Motassadeq, a Moroccan convicted of helping plan the Sept. 11 attacks.

But by early 2003, Ressam began to wear down, showing the effects of two years of interrogations and three years of solitary confinement that included "vicious verbal harassment" and a physical assault by a prison guard at the SeaTac federal prison shortly after 9/11, according to his defense lawyers. "Meetings became less frequent and less productive," and were then called off as Ressam sought to regain his health, the memo said.

Ressam's lawyers argued that Ressam's current condition does not diminish his past help and he is still willing to testify if called.

Mike Carter: 206-464-3706 or mcarter@seattletimes.com