For years, in total secrecy, they studied the black art of bioterrorism. They designed deadly, silent biological dart guns and hid them in fountain pens and walking sticks. They crunched lethal bacteria into suit buttons that could be worn unnoticed across borders. They rigged light fixtures and car tailpipes to loose an invisible spray of anthrax. They practiced germ attacks in airports and on the New York subway, tracking air currents and calculating the potential death toll. But they weren't a band of al-Qaida fanatics -- or enemies of any kind. They were biowarriors in the U.S. Army's Special Operations Division at Fort Detrick. From 1949 to 1969, at the jittery height of the Cold War, the division tested the nation's vulnerability to covert germ warfare -- and devised weapons for secret biological attacks if the United States chose to mount them. A few years ago, its story -- never before told in detail -- would have seemed a macabre footnote to U.S. history. Now, after the Sept. 11 attacks, the anthrax mailings and a steady stream of government warnings on terrorism, the fears of the 1950s have returned -- and the experiments of Fort Detrick's covert bioweapons makers suddenly resonate in a new era. In the biological realm, there is little that any terrorist group could concoct that Fort Detrick's "dirty tricks department," as veterans call it, didn't think up decades ago. But because of the division's scant recordkeeping and the fast-disappearing ranks of its aged scientist-warriors, the knowledge it acquired is being lost to history. One of the few survivors is Wallace Pannier, 76, who remembers standing in a Frederick County field watching sheep shot with what the Army called a "nondiscernible bioinoculator" -- a dart gun. The bosses demanded a dart so fine that it could penetrate clothing and skin unnoticed, then dissolve, leaving no trace in an autopsy. "If the sheep jumped, that meant people were going to jump, too," said Pannier, now living a quiet life tending his flowers and shrubs in Frederick. Once perfected, the dart gun astonished those who saw it in action. Charles Baronian, a retired Army weapons official, recalls a demonstration at Fort Bragg in North Carolina. "Twenty-five seconds after it was shot, the sheep just fell to the ground," said Baronian, 73. "It didn't bleat. It didn't move. It just fell dead. You couldn't help but be impressed." The rest of the Army's offensive biological weapons program thought big: 500-pound anthrax bombs that could contaminate entire cities. But the Special Operations Division -- known at Fort Detrick by its initials, SO -- studied biowarfare on a more intimate scale, figuring ways to kill an individual, disable a roomful of people or touch off an epidemic. 'Army has no records' The existence of the SO Division was revealed only six years after it shut down, in a 1975 Senate investigation into CIA abuses. Senators wanted to know why the CIA had retained a lethal stock of shellfish toxin and cobra venom after President Richard M. Nixon's 1969 order to destroy all biological weapons stocks. They found that the poisons had come from the SO Division under a CIA-Army project code-named MKNAOMI. But records show that even CIA bosses were stymied as they tried to get the facts on the SO Division. "The practice of keeping little or no record of the activity was standard MKNAOMI procedure," a CIA investigator wrote. The military offered little help, he added: "The Army has no records on MKNAOMI or on the Special Operations Division." In response to a Freedom of Information Act request from The Sun, the Army said no records of the Special Operations Division could be found. Nor is there any mention at the National Archives, which reclassified Fort Detrick's old biowarfare records after the Bush administration ordered agencies to withhold anything that might aid terrorists. Few SO Division veterans are still alive. Fewer still are willing to describe their work. They are not sure what is still classified and don't relish leaving biological horror tales for their grandchildren. "I just don't give interviews on that subject," said Andrew M. Cowan Jr., 74, the division's last chief, who is retired and living near Seattle. "It should still be classified -- if nothing else, to keep the information the division developed out of the hands of some nut." But it is possible to assemble a patchwork portrait from documents obtained by The Sun under the Freedom of Information Act, Senate investigative files and private document collections, including the National Security Archive in Washington and even the Church of Scientology, which long collected material on government mind-control research. And a few Detrick retirees who worked in the SO Division or collaborated with it spoke sparingly about what they know. Most are proud of their work, pointing out that the Soviet biological program was much larger and also developed assassination tools. Unsuccessful attacks The veterans still slip into biowarrior-speak, in which "good" means good-and-lethal. "It made a real nice aerosol," they'll say, or "That would give you real good coverage." All say that if the biological devices they made were used against humans, they never learned about it. But it is impossible to be certain, they say, because the program was strictly compartmented: One worker didn't know what another was doing, let alone what CIA or Special Forces did with the bioweapons. The 1975 Senate investigation revealed that the SO Division supplied biological materials for several planned CIA attacks, none of which were successful. In 1960, the CIA's main contact with the SO Division, Sidney Gottlieb, carried a tube of toxin-laced toothpaste to Africa in a plot to kill Congolese leader Patrice Lumumba. But the CIA station chief balked and pitched the poison into a river, a congressional investigation later revealed. Records suggest, though they do not prove, that the SO Division also supplied germs for CIA schemes to kill or sicken Cuban leader Fidel Castro, and that it came up with the poisoned handkerchief that the agency's drolly-named Health Alteration Committee sent to Iraqi Prime Minister Abdul Karim Qasim in 1963. (He survived.) Army Special Forces also asked the SO Division to design biological assassination weapons. Fort Detrick's engineers delivered five devices -- including the dart gun -- collectively known as the "Big Five." But records of what Special Forces did with the weapons remain classified, said Fort Bragg archivist Cynthia Hayden.

If the work sounds sinister today, there were doubters at the time, too. A 1954 Army document says high-ranking officials -- including George W. Merck, the pharmaceutical executive and top government adviser on biowarfare -- wanted to shut down the SO Division because they considered it "un-American." But Fort Detrick's rank and file rarely voiced such doubts. "We did not sit around talking about the moral implications of what we were doing," said William C. Patrick III, a Fort Detrick veteran who worked closely with the SO Division. "We were problem-solving." And if the orders came to unleash the weapons, Fort Detrick's biowarriors were ready. During the Vietnam War, William P. Walter, who supervised anthrax production at Fort Detrick and worked with the SO Division on projects, asked British intelligence agents for blueprints of the office occupied by North Vietnamese leader Ho Chi Minh. Plotting a covert germ assault is easier if the room's cubic footage and ventilation system are known, he says. "We thought if the president of the United States wants to kill somebody, we want to be able to do it," said Walter, now 78 and retired in Florida. Opening of the division A gun or a bomb leaves no doubt that a deliberate attack has occurred. But if someone is stricken with a sudden, fatal illness -- or an epidemic slashes across a crowded city -- there is no way of knowing whether anyone attacked, much less who. That was the key conclusion of the Pentagon's Committee on Biological Warfare in a secret October 1948 report on covert biowarfare. At the time, the United States feared a shadowy global enemy, organized in secret cells overseas and on U.S. soil --Communists. Echoing today's fears, the report said the United States "is particularly vulnerable" to covert germ attack because enemy agents "are present already in this country [and] there is no control exercised over the movements of people." Although it emphasized the threat to America, the report called for offensive capability. "Biological agents would appear to be well adapted to subversive use since very small amounts of such agents can be effective," the report said. "A significant portion of the human population within selected target areas may be killed or incapacitated." Setting an imaginative tone for what would follow, the report listed potential targets: "ventilating systems, subway systems, water supply systems ... stamps, envelopes, money, biologicals and cosmetics ... contamination of food and beverages." Seven months later, in May 1949, the Special Operations Division quietly opened at Fort Detrick. The other divisions there, created during and after World War II, focused on large-scale biological attack, said Walter, who completed a quadruple major at Mount St. Mary's College in Emmittsburg and went to work at Fort Detrick in 1951. At the time, planners regarded bioweapons as a valuable military option -- more devastating than chemical weapons, but more selective than a nuclear attack. "Biological agents can really cover more territory than nuclear weapons," Walter said. "Biological's better than nuclear because it doesn't destroy the buildings." Shrouded in secrecy Fort Detrick's other divisions had diabolical tricks of their own. For instance, Walter said, their scientists bred antibiotic-resistant bacteria to make standard Soviet and Chinese treatments useless against U.S. weapons. Still, the veterans say, Special Operations stood apart. You didn't apply for SO, you were chosen. And even within the tight-lipped world of Fort Detrick, the SO Division's secrecy was extraordinary. "Most of the people [at Fort Detrick] didn't know what was going on in SO," Pannier said. "And they got angry because you wouldn't tell 'em what was going on." When Pannier hitchhiked to Fort Detrick to take up his new assignment in 1946, he saw so many guard towers that he thought he had been sent to a prison. After three years there, he went home to Utah and completed a degree in bacteriology. When he returned, his former boss recommended him to the SO Division, "sort of a little Detrick within Detrick." SO Division personnel -- about 75 at the unit's peak -- didn't get the usual parking stickers. They had metal tags that could be removed from their cars when they traveled undercover. Pannier spent a night on the roof of the Pentagon taking air samples to rule out a bioattack before a visit by President John F. Kennedy. He was also assigned to see what germs were leaking from a Merck pharmaceutical plant on the Susquehanna River, observations that would be crucial to U.S. spies trying to identify Soviet bioweapons facilities. Pannier posed variously as a fisherman, an air-quality tester and a driver with a broken-down car. When East Bloc officials who were suspected of working in biowarfare labs traveled abroad, U.S. agents secretly swabbed their clothes so the SO Division could test for germs. Fanning out across the country, SO Division officers also played the role of bioterrorists in an era before the word had even been coined. Their usual mock weapons were two forms of bacteria, Bacillus globigii (BG) and Serratia marcescens (SM). Scientists thought both were harmless, though later research found that SM could cause illness or death in people with weakened immune systems. In an elaborate 1965 attempt to assess how travelers might be used to spread smallpox, SO Division officers loosed BG in the air at Washington National Airport and at bus stations in Washington, Chicago and San Francisco, then tracked its movement using air samplers disguised as suitcases. Tracking travelers' routes, Fort Detrick scientists plotted on a U.S. map the smallpox cases that would result from a real release. The germ-spreaders were never challenged, the report noted: "No terminal employee, passenger or visitor gave any outward indication of suspicion that something unusual was taking place." The next year, without alerting local officials, SO Division agents staged a mock attack on the New York subway, shattering light bulbs packed with BG powder on the tracks. "People could carry a brown bag with light bulbs in it and nobody would be suspicious," Pannier said. "But when [a bulb] would break, it would burst. ... The trains swishing by would get it airborne." The SO Division's report concluded that "similar covert attacks with a pathogenic agent during peak traffic periods could be expected to expose large numbers of people to infection and subsequent illness or death."