Glass shattered high above Seventh Avenue in Manhattan before dawn on a cold November morning in 1953. Seconds later, a body hit the sidewalk. Jimmy, the doorman at the Statler hotel, was momentarily stunned. Then he turned and ran into the hotel lobby. “We got a jumper!” he shouted. “We got a jumper!”

The night manager peered up through the darkness at his hulking hotel. After a few moments, he picked out a curtain flapping through an open window. It turned out to be room 1018A. Two names were on the registration card: Frank Olson and Robert Lashbrook.

Police officers entered room 1018A with guns drawn. They saw no one. The window was open. They pushed open the door to the bathroom and found Lashbrook sitting on the toilet, head in hands. He had been sleeping, he said, and “I heard a noise and then I woke up.”

“The man that went out the window, what is his name?” one officer asked.

“Olson,” came the reply. “Frank Olson.”

“In all my years in the hotel business,” the night manager later reflected, “I never encountered a case where someone got up in the middle of the night, ran across a dark room in his underwear, avoiding two beds, and dove through a closed window with the shade and curtains drawn.”

Facebook Twitter Pinterest The Statler Hotel in Manhattan. Photograph: Bettmann Archive

Leaving the police officers, the night manager returned to the lobby and, on a hunch, asked the telephone operator if any calls had recently been made from room 1018A. “Yes,” she replied – and she had eavesdropped, not an uncommon practice in an era when hotel phone calls were routed through a switchboard. Someone in the room had called a number on Long Island, which was listed as belonging to Dr Harold Abramson, a distinguished physician, less well known as an LSD expert and one of the CIA’s medical collaborators.

“Well, he’s gone,” the caller had said. Abramson replied: “Well, that’s too bad.”

To the first police officers on the scene, this seemed like another of the human tragedies they saw too often: a distressed or distraught man had taken his own life. They could not have known that the dead man and the survivor were scientists who helped direct one of the US government’s most highly classified intelligence programmes.

Early the next morning, one of Olson’s close colleagues drove to Maryland to break the terrible news to the dead man’s family. He told Alice Olson and her three children that Frank “fell or jumped” to his death from a hotel window. Naturally, they were shocked, but they had no choice other than to accept what they were told. Alice did not object when told that, given the condition of her husband’s body, family members should not view it. The funeral was held with a closed casket. There the case might have ended.

Decades later, however, spectacular revelations cast Olson’s death in a completely new light. First, the CIA admitted that, shortly before he died, Olson’s colleagues had lured him to a retreat and fed him LSD without his knowledge. Then it turned out that Olson had talked about leaving the CIA – and told his wife that he had made “a terrible mistake”. Slowly, a counter-narrative emerged: Olson was disturbed about his work and wanted to quit, leading his comrades to consider him a security risk. All of this led him to room 1018A.

Frank Olson had been one of the first scientists assigned to the secret US biological warfare laboratories at Fort Detrick in Frederick, Maryland during the second world war. There Olson began working with the handful of colleagues who would accompany him throughout his clandestine career. One was Harold Abramson. Others included ex-Nazi scientists who had been brought to work on secret missions in the US. For a time they worked on aerosol technologies – ways to spray germs or toxins on enemies and to defend against such attacks. Later, Olson met with American intelligence officers who had experimented with “truth drugs” in Europe.

Olson was discharged from the army in 1944, but remained at Fort Detrick on a civilian contract and continued his research into aerobiology. Several times he visited the secluded Dugway Proving Ground in Utah, which was used for testing “living biological agents, munitions and aerosol cloud production”. He co-authored a 220-page study entitled Experimental Airborne Infections, which described experiments with “airborne clouds of highly infectious agents”.

In 1949, he travelled to the Caribbean for Operation Harness, which tested the vulnerability of animals to toxic clouds. The next year, he was part of Operation Sea Spray, in which dust engineered to float like anthrax was released near San Francisco. He regularly travelled to Fort Terry, a secret army base on Plum Island, off the eastern tip of Long Island, which was used to test toxins too deadly to be brought on to the US mainland.

This was the period when senior army and CIA officers were becoming deeply alarmed at what they feared was Soviet progress toward mastering forms of warfare based on microbes. Their alarm led to the creation of the special operations division. Rumours about its work spread through offices and laboratories. Olson learned of it over an evening game of cards with a colleague, John Schwab, who unbeknown to him, had been named the division’s first chief. Schwab invited him to join. Olson accepted immediately.

Less than a year later, Olson succeeded Schwab as chief of the special operations division. His job description was vague but tantalising: collect data “of interest to the division, with particular emphasis on the medico-biological aspects”, and coordinate his work with “other agencies conducting work of a similar or related nature”. That meant the CIA.

Olson’s speciality was “the airborne distribution of biological germs”, according to one study. “Dr Olson had developed a range of lethal aerosols in handy sized containers. They were disguised as shaving cream and insect repellants. They contained, among other agents, staph enteroxin, a crippling food poison; the even more deadly Venezuelan equine encephalomyelitis; and most deadly of all, anthrax ... Further weapons he was working on included a cigarette lighter which gave out an almost instant lethal gas, a lipstick that would kill on contact with skin and a neat pocket spray for asthma sufferers that induced pneumonia.”

Facebook Twitter Pinterest Frank Olson in 1952. Photograph: AP

By the time Olson stepped down as chief of the special operations division in early 1953, complaining that the pressures of the job aggravated his ulcers, he had joined the CIA. He stayed with the division, which was officially part of the army but functioned as a CIA research station hidden within a military base. There he came to know Sidney Gottlieb and his deputy, Robert Lashbrook, the two scientists who would soon be running a top-secret CIA project codenamed MK-Ultra.

Gottlieb was the CIA’s chief poison-maker. Over two decades, he oversaw medical experiments and “special interrogation” projects in which hundreds of people were tormented and many minds were permanently shattered. During this period, there was an obsession at the CIA: there is a way to control the human mind, and if it can be found, the prize will be nothing less than global mastery. MK-Ultra was a top secret programme of experiments in mind control that used, as its basic formula, doses of LSD given to “expendables”. Gottlieb wanted to discover how much LSD a human being could take. Could there be a breaking point, he wondered – a dose so massive that it would shatter the mind and blast away consciousness, leaving a void into which new impulses or even a new personality could be implanted?

In his laboratory at Fort Detrick, Olson directed experiments that involved gassing or poisoning laboratory animals. These experiences disturbed him. “He’d come to work in the morning and see piles of dead monkeys,” his son Eric later recalled. “That messes with you. He wasn’t the right guy for that.”

Olson also saw human beings suffer. Although not a torturer himself, he observed and monitored torture sessions in several countries.

“In CIA safe-houses in Germany,” according to one study, “Olson witnessed horrific brutal interrogations on a regular basis. Detainees who were deemed ‘expendable’ – suspected spies or moles, security leaks, etc – were literally interrogated to death in experimental methods combining drugs, hypnosis and torture, to attempt to master brainwashing techniques and memory erasing.”

As Thanksgiving approached in 1953, Olson received an invitation to gather on Wednesday 18 November for a retreat at a cabin on Deep Creek Lake in western Maryland. This retreat was one in a series that Gottlieb convened every few months. Officially, it was a coming-together of two groups: four CIA scientists from the technical services staff, which ran MK-Ultra, and five army scientists from the special operations division of the chemical corps. In reality, these men worked so closely together that they comprised a single unit. They were comrades in search of cosmic secrets. It made sense for them to gather, discuss their projects and exchange ideas in a relaxed environment.

The first 24 hours at the retreat were uneventful. On Thursday evening, the group gathered for dinner and then settled back for a round of drinks. Lashbrook, Gottlieb’s deputy, produced a bottle of Cointreau and poured glasses for the company. Several, including Olson, drank heartily. After 20 minutes, Gottlieb asked if anyone was feeling odd. Several said they were. Gottlieb then told them their drinks had been spiked with LSD.

The news was not well received. Even in their altered state, the subjects could understand what had been done to them. Olson was especially upset. According to his son Eric, he became “quite agitated and was having a serious confusion with separating reality from fantasy”. Soon, though, he and the others were carried away into a hallucinatory world. Gottlieb later reported that they were “boisterous and laughing … unable to continue the meeting or engage in sensible conversations”. The next morning, they were in only slightly better shape. The meeting broke up. Olson headed back to Frederick. By the time he arrived, he was a changed man.

The next morning, 23 November, Olson showed up early at Fort Detrick. His boss, Vincent Ruwet, arrived soon after. Neither were in good shape. More than four days had passed since they had been given LSD without their knowledge. Ruwet later called it “the most frightening experience I have ever had or hope to have”.

Olson began pouring out his doubts and fears. “He appeared to be agitated, and asked me if I should fire him or he should quit,” Ruwet later recalled. Ruwet tried to calm him, assuring him that his work was excellent, and recognised as such. Slowly, Olson was persuaded that resignation was too extreme a reaction.

By this time MK-Ultra had been under way for seven months. It was one of the government’s deepest secrets, guarded by security that was, as Olson had been told when he joined the special operations division, “tighter than tight”. Barely two dozen men knew its true nature. Nine had been at Deep Creek Lake. Several of those had been surreptitiously dosed with LSD. Now one of them seemed out of control. This was no light matter for men who believed that the success or failure of MK-Ultra might determine the fate of the US, and all humanity.

Olson had spent 10 years at Fort Detrick and knew most, if not all, of the special operation division’s secrets. He had repeatedly visited Germany and brought home pictures from Heidelberg and Berlin, where the US military maintained clandestine interrogation centres. He was one of several special operations division scientists who were in France on 16 August 1951, when an entire French village, Pont-Saint-Esprit, was mysteriously seized by mass hysteria and violent delirium that afflicted more than 200 residents and caused several deaths; the cause was later determined to have been poisoning by ergot, the fungus from which LSD was derived. Perhaps most threatening of all, if US forces did indeed use biological weapons during the Korean war – for which there is circumstantial evidence but no proof – Olson would have known. The prospect that he might reveal any of what he had seen or done was terrifying.

“He was very, very open and not scared to say what he thought,” Olson’s friend and colleague Norman Cournoyer later recalled. “He did not give a damn. Frank Olson pulled no punches at any time … That’s what they were scared of, I am sure.”

Olson’s doubts deepened. In spring 1953, he visited the top-secret Microbiological Research Establishment at Porton Down in Wiltshire, where government scientists were studying the effects of sarin and other nerve gases. On 6 May, a volunteer subject, a 20-year-old soldier, was dosed with sarin there, began foaming at the mouth, collapsed into convulsions, and died an hour later. Afterward, Olson spoke about his discomfort with a psychiatrist who helped direct the research, William Sargant.

A month later, Olson was back in Germany. On that trip, according to a later reconstruction of his travels, Olson “visited a CIA safe house near Stuttgart [where] he saw men dying, often in agony, from the weapons he had made.” After stops in Scandinavia and Paris, he returned to Britain and visited Sargant again. Immediately after their meeting, Sargant wrote a report saying that Olson was “deeply disturbed over what he had seen in CIA safe houses in Germany” and “displayed symptoms of not wanting to keep secret what he had witnessed”. He sent his report to his superiors with the understanding that they would forward it to the CIA. Sargant said later: “There were common interests to protect.”

Five days after being dosed with LSD, Olson was still disoriented. Ruwet, his boss at the special operations division, called Gottlieb to report this. Gottlieb asked him to bring Olson in for a chat. At their meeting, Gottlieb later testified, Olson seemed “confused in certain areas of his thinking”. He made a quick decision: Olson must be taken to New York City and delivered to the physician most intimately tied to MK-Ultra – Harold Abramson.

Alice Olson was told that Abramson was chosen because her husband “had to see a physician who had equal security clearance so he could talk freely”.

That was partly true. Abramson was not a psychiatrist, but he was an MK-Ultra initiate. Gottlieb knew that Abramson’s first loyalty was to MK-Ultra – or, as he would have put it, to the security of the US. That made him the ideal person to probe Olson’s inner mind. Olson told Abramson that ever since the Deep Creek Lake retreat, he had been unable to work well. He could not concentrate and forgot how to spell. He could not sleep. Abramson sought to reassure Olson, who seemed to relax afterwards.

A week had passed since Olson was given LSD at Deep Creek Lake. He planned to return to his family for Thanksgiving dinner. The day after seeing Abramson, accompanied by Lashbrook and Ruwet, he boarded a flight to Washington. An MK-Ultra colleague was waiting when they landed. Ruwet and Olson got into his car for the drive to Frederick. Soon after they set off, Olson’s mood changed. He asked that the car be stopped. Olson turned to Ruwet and announced that he felt “ashamed to meet his wife and family” because he was “so mixed up”.

“What do you want me to do?” Ruwet asked.

“Just let me go. Let me go off by myself.”

“I can’t do that.”

“Well then, just turn me over to the police. They’re looking for me anyway.”

Ruwet suggested Olson return to New York for another session with Abramson. Olson agreed, so they took a taxi to Abramson’s weekend home on Long Island. Abramson spent about an hour with Olson, followed by 20 minutes with Lashbrook.

The next morning, Abramson, Lashbrook and Olson drove back to Manhattan. During a session at his Fifty-Eighth Street office, Abramson persuaded Olson that he should agree to be hospitalised as a voluntary patient at a Maryland sanatorium. Olson and Lashbrook left, registered at the Statler Hotel, and were given room 1018A.

Over dinner at the Statler, Olson told Lashbrook that he was looking forward to his hospitalisation. He mused about books he would read. Lashbrook later said he was “almost the Dr Olson I knew before the experiment”. The two returned to their room. Olson washed his socks in the sink, watched TV for a while and lay down to sleep.

At 2.25am, he went out the window.

Every secret service needs officers who specialise in cleaning up messes. In the CIA of the 1950s, those officers worked for Sheffield Edwards at the Office of Security. The cover-up he directed in the hours and days after Frank Olson died was a model of brisk efficiency.

With the calm self-assurance for which he was known at the CIA, Edwards announced how the cover-up would unfold. First, the New York police would be persuaded not to investigate, and to cooperate in misleading the press. Second, a fake career – a “legend” – would be constructed for Lashbrook, who, as the sole witness, would be questioned by investigators and could under no circumstances be recognised as working for the CIA, much less MK-Ultra. Third, the Olson family would have to be informed, placated and kept cooperative.

While Alice, at home in Maryland, was being informed of her husband’s death, Lashbrook was welcoming the CIA cavalry to room 1018A at the Statler in New York. It took the form of a single officer. In internal reports, he is called “Agent James McC”. Later, he was identified as James McCord, who would go on to become a footnote to US political history as one of the Watergate burglars. McCord had previously been an FBI agent specialising in counterintelligence. Making police investigations evaporate was one of his specialities.

As soon as Edwards called McCord before dawn on 28 November, he swung into action. He took the first morning plane to New York and arrived at the Statler about 8am. He spent an hour questioning Lashbrook and then, at about 9.30am, advised him to go to the morgue at Bellevue hospital, as the police had requested, to identify Olson’s body. While he was away, McCord minutely searched room 1018A and nearby rooms.

Shortly after noon, Lashbrook returned to the Statler, where McCord was waiting. Over the next few hours, Lashbrook made a series of telephone calls. One was to Gottlieb. When he hung up, he told McCord that Gottlieb had instructed him to go to Abramson’s office, pick up a report and take it back to Washington by hand. Lashbrook carried Abramson’s report to Washington on the midnight train. CIA security officers in New York took care of the remaining details. The investigating police detective concluded that Olson had died from multiple fractures “subsequent upon a jump or fall”. That became the official narrative.

Despite the successful cover-up, Olson’s death was a near-disaster for the CIA. It came close to threatening the very existence of MK-Ultra.

Gottlieb and his bosses at the CIA might have taken this as a moment for reflection. In light of this death, they could have reasoned, further experiments with psychoactive drugs should be stopped, at least on unwitting subjects. Instead, they proceeded as if Olson’s death had never happened.

On 12 June 1975, the Washington Post ran a story about an army scientist who had been drugged with LSD by the CIA, reacted badly and jumped out of the window of a New York hotel. This story, with its lurid mix of drugs, death and the CIA, proved irresistible. For the next several days, reporters barraged the CIA with demands to know more. The Olson family called a press conference in the family’s back yard. Alice read a statement saying that the family had decided to “file a lawsuit against the CIA, perhaps within two weeks, asking several million dollars in damages”. She insisted that her husband had “not acted irrational or sick” during the last days of his life, but was “very melancholy” and “said he was going to leave his job”.

“Since 1953, we have struggled to understand Frank Olson’s death as an inexplicable ‘suicide,’” she said. “The true nature of his death was concealed for 22 years.”

Besides announcing plans to sue the CIA, the Olson family also asked the New York police department to open a new investigation. The Manhattan district attorney, Robert Morgenthau, replied immediately, promising that his office would begin “looking into certain aspects” of the case.

Alarm bells went off at the White House after the Olson family announced its plan to sue the CIA. A lawsuit, if allowed to proceed, would give the family, as well as homicide detectives in New York, a tool they could use to force disclosure of deep secrets. President Ford’s chief of staff, Donald Rumsfeld, and his deputy, Dick Cheney, recognised the danger. Cheney warned Rumsfeld in a memo that a lawsuit might force the CIA “to disclose highly classified national security information”. To head off this disaster, he recommended that Ford make a public “expression of regret” and “express a willingness to meet personally with Mrs Olson and her children”.

Facebook Twitter Pinterest President Ford (centre right) in the Oval Office with the Olson family. Photograph: Bettmann/Bettmann Archive

Ford took his aides’ advice. He invited Alice and her three adult children to the White House. On 21 July 1975, they met in the Oval Office. It was a unique historical moment: the only time an American president has ever summoned the family of a CIA officer who died violently and apologised on behalf of the US government. Later, they met with CIA director William Colby at the agency’s HQ in Langley, Virginia. He apologised for what he called a “terrible thing” that “should never have happened”.

“Some of our people were out of control in those days,” Colby said. “They went too far. There were problems of supervision and administration.”

White House lawyers offered the Olson family $750,000 in exchange for dropping its legal claims. After some hesitation, the family accepted. Congress passed a special bill approving the payment. And that would have closed the case if Frank Olson had remained quiet in his grave.

At Olson’s funeral, Gottlieb had told grieving relatives that if they ever had questions about “what happened”, he would be happy to answer them. More than two decades later, at the end of 1984, they decided to accept his offer and called to arrange an appointment. When Alice, Eric and Nils Olson appeared at his door, his first reaction was relief.

“I’m so happy you don’t have a weapon,” Gottlieb said. “I had a dream last night that you all arrived at this door and shot me.”

Eric was taken aback. Later, he came to marvel at what he saw as Gottlieb’s manipulative power. “Before we even got through the door, we were apologising to him and reassuring him,” he said. “It was a brilliant and sophisticated way of turning the whole thing around.”

He began by telling the family what had happened at Deep Creek Lake on 19 November 1953. Olson and others were given LSD, he said, as part of an experiment to see “what would happen if a scientist were taken prisoner and drugged – would he divulge secret research and information?” Then he began musing about Olson. “Your father and I were very much alike,” he told Eric. “We both got into this because of patriotic feeling. But we both went a little too far, and we did things that we probably should not have done.”

That was as close to confession as Gottlieb ever came. He would not say what aspects of MK-Ultra went “a little too far”, or what he and Olson did that they “probably should not have done”. Nor would he entertain questions about inconsistencies in the story of Olson’s death. When Eric pressed him, he reacted sharply.

As the family were rising to leave, Gottlieb pulled Eric aside. “You are obviously very troubled by your father’s suicide,” he said. “Have you ever considered getting into a therapy group for people whose parents have committed suicide?” Eric did not follow that suggestion, but it left a deep impression on him. For years, he had been confused and depressed by the story of his father’s death. Only after meeting Gottlieb, however, did he resolve to bring his search for truth to the centre of his life.

“I didn’t have the confidence then in my scepticism to ignore his ploys, but when he made that therapy group suggestion – that was the moment when he overplayed his hand,” he said. “At that moment, I understood how much Gottlieb had a stake in defusing me. And it was also at that moment that the determination to show that he had played a role in murdering my father was born.”

Eric Olson waited another decade – until after his mother died – before taking his next step: arranging to exhume his father’s body. Several reporters stood near him as a backhoe clawed through the earth at Linden Hills cemetery in Frederick, Maryland, on 2 June 1994.

A forensic pathologist, James Starrs of George Washington University Law School, spent a month studying Olson’s body. When he was finished, he called a news conference. His tests for toxins in the body, he reported, had turned up nothing. The wound pattern, however, was curious. Starrs had found no glass shards on the victim’s head or neck, as might be expected if he had dived through a window. Most intriguingly, although Olson had reportedly landed on his back, the skull above his left eye was disfigured.

“I would venture to say that this hematoma is singular evidence of the possibility that Dr Olson was struck a stunning blow to the head by some person or instrument prior to his exiting through the window of room 1018A,” Starrs concluded. Later he was more emphatic: “I think Frank Olson was intentionally, deliberately, with malice aforethought, thrown out of that window.”

Besides conducting the autopsy, Starrs interviewed people connected to the case. One was Gottlieb. The two men met on a Sunday morning at Gottlieb’s home in Virginia. Starrs later wrote that it was “the most perplexing of all the interviews I conducted”.

Starr wrote: “I was emboldened to ask how he could so recklessly and cavalierly have jeopardised the lives of so many of his own men by the Deep Creek Lodge experiment with LSD. ‘Professor,’ he said without mincing a word, ‘you just do not understand. I had the security of this country in my hands.’ He did not say more, nor need he have done so. Nor did I, dumbfounded, offer a rejoinder. The means-end message was pellucidly clear. Risking the lives of the unwitting victims of the Deep Creek experiment was simply the necessary means to a greater good, the protection of the national security.”

Because Olson’s survivors had signed away their right to legal relief when they accepted their $750,000 compensation payment in 1975, they could not sue the CIA. Although Starr’s report and other discoveries sharpened Eric’s already powerful suspicion that foul play lay behind his father’s death, he could not prove it. Recognising that painful fact, he and his brother decided that it was finally time to reinter their father’s body. On 8 August 2002, the day before the reburial, he called reporters to his home and announced that he had reached a new conclusion about what had happened to his father.

“The death of Frank Olson on 28 November 1953 was a murder, not a suicide,” he declared. “This is not an LSD drug-experiment story, as it was represented in 1975. This is a biological warfare story. Frank Olson did not die because he was an experimental guinea pig who experienced a ‘bad trip’. He died because of concern that he would divulge information concerning a highly classified CIA interrogation program in the early 1950s, and concerning the use of biological weapons by the United States in the Korean War.”

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In 2017, Stephen Saracco, a retired New York assistant district attorney who had investigated the Olson case and remained interested in it, made his first visit to the hotel room where Olson spent his final night. Looking around the room, Saracco said, raised the question of how Olson could have done it.

“If this would have been a suicide, it would have been very difficult to accomplish,” Saracco concluded. “There was motive to kill him. He knew the deepest, darkest secrets of the cold war. Would the American government kill an American citizen who was a scientist, who was working for the CIA and the army, if they thought he was a security risk? There are people who say: ‘Definitely.’”

This is an edited extract from Poisoner in Chief: Sidney Gottlieb and the CIA Search for Mind Control, published by Henry Holt & Co on 10 September and available at guardianbookshop.co.uk

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