Mohammed was said to be initially resistant to rough treatment and inclined to give disinformation.

By SCOTT SHANE

WASHINGTON - In a makeshift prison in the north of Poland, Al Qaeda’s engineer of mass murder faced off against his Central Intelligence Agency interrogator. It was 18 months after the 9/11 attacks, and the invasion of Iraq was giving Muslim extremists new motives for havoc. If anyone knew about the next plot, it was Khalid Shaikh Mohammed.
The interrogator, whose nickname is “Deuce” Martinez, a soft-spoken analyst who spoke no Arabic, had turned down a C.I.A. offer to be trained in waterboarding. He chose to leave the infliction of pain and panic to others. Mr. Martinez came in after the rough stuff, the ultimate good cop with the classic skills: an unimposing presence, inexhaustible patience and a willingness to listen to the gripes and musings of a pitiless killer in rambling, imperfect English. He achieved a rapport with Mr. Mohammed that astonished his fellow C.I.A. officers.
A canny opponent, Mr. Mohammed mixed disinformation and braggadocio with details of plots, past and planned. Eventually, he grew loquacious. “They’d have long talks about religion, comparing notes on Islam and Mr. Martinez’s Catholicism, one C.I.A. officer recalled. And, the officer added, there was one other detail no one could have predicted: “He wrote poems to Deuce’s wife.
The story of Mr. Martinez’s role in the C.I.A.’s interrogation program, including his contribution to the first capture of a major figure in Al Qaeda, provides the closest look to date beneath the blanket of secrecy that hides the program from terrorists and from critics who accuse the agency of torture.
In the Hollywood cliche, a torturer shouts questions at a bound terrorist while inflicting excruciating pain. The C.I.A. program worked differently. A paramilitary team put on the pressure, using cold temperatures, sleeplessness, pain and fear to force a prisoner to talk. When the prisoner signaled assent, the tormenters stepped aside. After a break , Mr. Martinez or another interrogator took up the questioning.
Mr. Martinez’s success at building a rapport with the most ruthless of terrorists goes to the heart of the interrogation debate.
Did it suggest that traditional methods alone might have obtained the same information or more- Or did Mr. Mohammed talk so expansively because he feared more of the brutal treatment he had already endured?
A definitive answer is unlikely under the Bush administration, which has insisted in court that not a single page of 7,000 documents on the program can be made public.
Mr. Martinez declined to be interviewed; his role was described by colleagues. General Michael V. Hayden, director of the C.I.A., and a lawyer representing Mr. Martinez asked that he not be named in this article, saying that the former interrogator believed that its use would invade his privacy and might jeopardize his safety. This article uses his nickname instead of his real first name. (An editors’ note on this subject can be viewed at nytimes.
com/world.)
The fact that Mr. Martinez, a career narcotics analyst who did not speak the terrorists’ languages and had no interrogation experience, would end up as a crucial player captures the makeshift nature of the program. Officials acknowledge that it was cobbled together under enormous pressure in 2002 .
The C.I.A. made the momentous decision to use harsh methods the United States had long condemned. It borrowed its techniques from an American military program modeled on the torture repertories of the Soviet Union and other coldwar adversaries .
Whether it was a result of a fear of waterboarding, the patient trust-building mastered by Mr. Martinez or the demoralizing effects of isolation, Mr. Mohammed and some other prisoners had become quite compliant. Asked, for example, how he would smuggle explosives into the United States, Mr. Mohammed told C.I.A officers that he might send a shipping container from Japan loaded with personal computers, half of them packed with bomb materials, according to a foreign official briefed on the episode.
“It was to understand the mind of a terrorist - how a terrorist would do certain things, the foreign official said of the discussions of hypothetical attacks.
Colleagues say Mr. Martinez, then 36, threw himself into the new work with a passion in 2002 in Pakistan. When Abu Zubaydah, another top Qaeda leader, was captured on March 28, 2002, in Faisalabad, Pakistan, he was flown to Thailand, to the first of the “black sites, the agency’s interrogation facilities for major Qaeda figures. It was at the Thai jail, not far from Bangkok, that Mr. Martinez, then 36, first tried his hand at interrogation on Abu Zubaydah .It was also there, as previously reported, that the C.I.A. would first try physical pressure to get information, including the near-drowning of waterboarding. Senior Federal Bureau of Investigation officials thought such methods unnecessary and unwise. Their agents got Abu Zubaydah talking without the use of force, and he revealed the central role of Mr. Mohammed in the 9/11 plot.
With Abu Zubaydah’s case, the pattern was set. With a new prisoner, the interrogators, like Mr. Martinez, would open the questioning. If officers believed the prisoner was holding out, paramilitary officers would move in to manhandle the prisoner.
Within days of the capture of Khalid Shaikh Mohammed on March 1, 2003, he was flown to Afghanistan and then on to Poland, where the most important of the C.I.A.’s black sites had been established. The tough treatment began. By several accounts, he proved especially resistant . But he talked most freely to Mr. Martinez. Mr. Martinez shared a few attributes with his adversary that he could exploit as he sought his secrets. They were close in age, approaching 40; they had attended public universities in the American South; they were both religious; and they were both fathers.
At times, Mr. Mohammed would grow depressed, complaining about being separated from his family and ranting about his cell or his food.
As time passed, Mr. Mohammed provided more detail on Al Qaeda’s structure, its past plots and its aspirations.
The intelligence riches gleaned from Mr. Mohammed were reflected in the report of the national 9/11 commission.
Mr. Martinez eventually left the agency for more lucrative work with government contractors. He now works for Mitchell & Jessen Associates, a consulting company run by former military psychologists .
And his new employer sent Mr. Martinez right back to the agency. For now, the unlikely interrogator of the man perhaps most responsible for the horrors of 9/11 teaches other C.I.A. analysts the arcane art of tracking terrorists.