I n 1973, Harry Sheng was working as a mechanical engineer for Sparton Corporation, a defense contractor in Jackson, Michigan, when his mother got sick back in China. Sheng was among thousands of ethnic Chinese scientists then living in the United States, the early pioneers in what would become a sizable swath of the American research force. A native of Jiangsu province and a naturalized U.S. citizen, he had left home just before Mao Zedong came to power in 1949, and he hadn’t seen his friends or relatives in China since. But now relations between the two countries were improving. In 1971, the U.S. pingpong team had toured the mainland, and the following year, President Richard Nixon had made the historic visit that restored contact between the countries’ leaders. Sheng had just started his job at Sparton, but he loved his mother dearly. He and his wife booked flights. On Nixon’s trip, the two sides had agreed to set up exchanges in science, which, like pingpong, was seen as a way to improve ties between the United States and China. Washington hoped that rapprochement with China would destabilize the Communist-led independence forces the U.S. military was fighting in Vietnam and increase America’s leverage over the Soviet Union. For Chinese American scientists like Sheng, the thaw presented a simpler opportunity: a chance to return to their hometowns, eat their favorite foods, and hug the parents they had left behind decades earlier. Sheng was a gentle man who collected coins in his spare time and never missed a church service. Before joining Sparton, he had worked for a decade for the defense contractor Lear Siegler, where he held a secret-level U.S. government security clearance. In 1972, he had been interviewed by an FBI agent in Grand Rapids, Michigan, for an undisclosed purpose. According to an FBI memo, Sheng “declared his anti-communist feelings, his love and patriotism for America” and “denied any contact between himself and Communist agents.” But after Sheng and his wife returned from their 1973 visit to China, the U.S. government’s scrutiny intensified. Agents from the FBI, the CIA, and the Department of Defense grilled him about everything he had done on his sightseeing tour, he later said. Sparton inexplicably transferred him to a drafting position — a move that he perceived as a demotion — and then, in 1975, laid him off. He subsequently received two offers from other defense firms, Raytheon and Hazeltine, only to have them suddenly rescinded, he said. He never held a permanent position in his field again.

Sheng was baffled. He had served in the marines for Chiang Kai-shek’s Nationalist forces in the Chinese Civil War, against Mao’s Liberation Army, and had no desire to live under Communist rule. The FBI sometimes investigated undocumented immigrants, including in San Francisco’s Chinatown, but Sheng had married a white woman from Iowa, and he knew few other Chinese Americans in the Grand Rapids area. Sheng flew the American flag outside his house, and in his encounters with federal agents, he had seemingly done everything right. In a 1973 interview, an FBI agent asked him what he would do if the Communists pressured his relatives living in China. Sheng replied that he would immediately report the matter to the FBI. He spent years searching for answers, but he never got the one that would have explained all the undue scrutiny: He was one of what appear to have been hundreds of people surveilled under a previously unreported FBI program that targeted ethnic Chinese scientists and students living in the United States. Titled “Chinese Communist Contacts with Scientists in the U.S.” and listed under the umbrella “IS-CH,” or Internal Security-China, the classified program dates to the late 1960s, when Chinese weapons development spurred intense anxiety within the U.S. government. It continued until at least 1978. The program’s targets included several prominent scientists and scholars, most notably physicist Chang-Lin Tien, who later became chancellor of the University of California, Berkeley. Under J. Edgar Hoover, the FBI pursued a slew of misguided counterintelligence investigations, hounding civil rights activists, feminist groups, and left-leaning scholars. The bureau’s broader surveillance of scientists during the Cold War is well documented; among those targeted was theoretical physicist and Manhattan Project contributor Richard Feynman. The newly obtained documents show that alongside such efforts, the bureau singled out Chinese American scientists because of their ethnicity — and that it did so even after the Senate’s Church Committee, formed in 1975, exposed some of the most egregious intelligence abuses of the era, many involving government surveillance of Americans on U.S. soil. Program documents that I obtained through a Freedom of Information Act request, as well as the files of individual scientists who were surveilled, suggest a wide-ranging effort. They also show an early tendency within the U.S. national security establishment to assume that major scientific advances in China were the product of theft — a logic that would inform cases for decades to come. Zuoyue Wang, a historian at California State Polytechnic University in Pomona whose research focuses on U.S.-China scientific relations during the Cold War, said the documents show an inclination to assume that “American scientists with an immigrant background are the primary sources of illicit technological transfers,” when in reality the story of technological advancement is much more complex. The program’s effects reverberate today, at a moment when combating economic espionage and scientific theft from China are among the FBI’s top priorities. Over the past decade, the Justice Department has brought dozens of cases involving ethnic Chinese scientists. It has also brought a number of cases against non-Chinese, most notably Charles Lieber, the chair of Harvard University’s chemistry department, who was charged last week with making false statements in connection to grant money he received from the Chinese government. Critics allege that the broader campaign against intellectual property theft is often informed by the same thinking that drove the Chinese scientist program. The FBI did not respond to a request for comment about the program or about ongoing complaints of bias against Chinese Americans both within and outside the bureau.

The focus on economic espionage began under the Obama administration, but as tensions with China have heightened under President Donald Trump, cases have proliferated. In 2018, the Justice Department’s National Security Division launched an effort focused on intellectual property theft called the China Initiative. “No country presents a broader, more severe threat to our ideas, our innovation, and our economic security than China,” FBI Director Christopher Wray said at the time. The FBI now says it has more than 1,000 active investigations into Chinese industrial espionage, spanning all 50 states. Among the cases brought by federal prosecutors are clear-cut instances of technological theft, such as one against Chinese wind turbine firm Sinovel, which in 2018 was convicted of stealing the source code for operating wind turbines from Wisconsin-based American Superconductor. But not all the cases have panned out, and critics see bias in who is charged. In a 2019 analysis of 136 cases brought under the Economic Espionage Act, Andrew Chongseh Kim, a visiting scholar at South Texas College of Law, found that 21 percent of defendants with Chinese names were ultimately not convicted of espionage or other major crimes, about twice the rate of defendants from other ethnic groups, meaning that they were either acquitted at trial or the most serious charges against them were downgraded or dropped. One such botched investigation involved Xiaoxing Xi, an expert at Temple University in Philadelphia on superconducting thin films, which carry electricity without resistance at very low temperatures. In 2015, Xi was the interim chair of the university’s physics department when he was charged with trying to transfer to China designs for a thin-film device called the pocket heater, which is made by Superconductor Technologies Inc. based in Austin, Texas. The charges against Xi were dropped after his lawyer submitted affidavits from other scientists — including the inventor of the pocket heater himself — making clear that there was little substance to the allegations. The existence of a dedicated FBI program to surveil Chinese scientists, Xi told me, “sounds eerily like what is happening today.”

Harry Sheng and his wife, Irene, in the 1960s. Photo: Courtesy of Ling Woo Liu

I first learned about the FBI’s Chinese scientist program in a 2016 email from a Bay Area woman named Ling Woo Liu. I was part-way through writing a book, “The Scientist and the Spy: A True Story of China, the FBI, and Industrial Espionage,” on an FBI investigation involving a Chinese-born scientist. That case was set in motion in 2011, when a researcher named Robert Mo was chased down by sheriff’s deputies near a Monsanto contract field in Iowa. Mo had been driving a rental van while his colleague from a Beijing agriculture company surveyed the field for stray ears of corn. The FBI suspected the men of trying to reverse-engineer Monsanto and DuPont Pioneer hybrid corn seed. Having spent eight years as a reporter in China, I was clear-eyed about the existence of industrial espionage, and my reporting suggested that Mo and his colleagues were trying to glean trade secrets from Monsanto and DuPont Pioneer. But the FBI’s reaction seemed disproportionate to the crime. The cornfield incident sparked a two-year investigation in which the bureau flew surveillance planes over the heartland, collected evidence using a Foreign Intelligence Surveillance Act warrant, and staged an elaborate airport bust involving microwave popcorn bags — all in the name of protecting the intellectual property of two giant corporations. The U.S. government spent untold amounts of money investigating and prosecuting Mo, ostensibly to safeguard American innovation. And yet, by the time I had finished the book, Monsanto had been acquired by the German conglomerate Bayer, meaning that it was no longer even American. In the course of my reporting, I had talked with former prosecutors, intelligence analysts, and community organizers who detailed a longstanding history of bias against Chinese Americans within the bureau. So when Liu emailed me out of the blue to say that she had insight into that history, I was intrigued. We set up a phone call. Harry Sheng had been a close friend of her parents, Liu told me. After several years of failing to find a steady job, his wife, Irene, began nannying for Liu and her sisters. The Shengs later followed the Liu family to California. The Shengs did not have children of their own, and they attended all of the girls’ birthday parties, dance recitals, and soccer games. The sisters referred to them as “aunt” and “uncle” throughout their lives. Liu did not learn why Sheng had abruptly stopped working until decades later, after his death. Then, while sorting through his belongings, she and her sisters found a packet of papers containing years’ worth of letters from Sheng to Michigan lawmakers, seeking answers about why he had been laid off. Liu filed a FOIA request for Sheng’s FBI file. When it arrived, she noticed the label “IS-CH” at the top of many documents. One 1972 letter in the file instructed agents in Detroit that when interviewing Sheng, they should follow “instructions set forth in Bureau airtel to all offices, dated 9/22/71, captioned ‘Chinese Communist Contacts with Scientists in the U.S.’”

“Have you heard of this program?” she asked me. I hadn’t, but I knew of other scientists who had been surveilled during that period. I filed a FOIA request for documents connected to the program. Two years later, after I had all but given up, the FBI sent me 105 pages of documents. They are marred by redactions, and the release only covers the year 1967, even though the program continued at least into the late 1970s. The FBI declined to release an additional 107 pages, on the basis that they were exempted from disclosure, would violate individuals’ privacy, or reveal the agency’s sources and methods. (At one point, the bureau redacted the name of a person described as “Communist Party Chairman” — Mao Zedong.) A Washington, D.C.-based law firm helped me appeal the bureau’s decisions last spring. The request is still under review. But through additional FOIA requests, I obtained the files of other scientists surveilled under the program that helped round out the picture. The Chinese scientist program has its origins in the 1950s Red Scare, when the FBI investigated Chinese-born rocket scientist Tsien Hsue-Shen (later known as Qian Xuesen) for being a suspected member of the U.S. Communist Party. Tsien, whose story is detailed in Iris Chang’s book “Thread of the Silkworm,” was a talented researcher at the California Institute of Technology in Pasadena, where he worked on classified government projects and helped found Caltech’s Jet Propulsion Laboratory. In 1950, the year after Mao rose to power in China, FBI agents questioned Tsien, and the U.S. military revoked his security clearance. Recent research suggests that for a while, Tsien was a party member, but that he showed little interest in aiding China. That changed when the FBI began scrutinizing his loyalty, making it impossible for him to do serious work in the United States. In the wake of the Cultural Revolution, China’s Communist leaders were openly courting overseas Chinese scholars, and with his job prospects in America diminished, Tsien tried to leave for China with his family. Worried that he was trying to smuggle out valuable defense information, U.S. immigration agents stopped him at the border. For the next five years, he remained under near-constant FBI surveillance. Finally, in 1955, the United States let him leave. The decision had ominous repercussions. In Beijing, he was given a hero’s welcome and put to work on weapons research. In 1966, with Tsien’s help, China tested a nuclear-tipped missile. The following year, it stunned the world by testing a hydrogen bomb.

Tsien Hsue-Shen, left, director of Caltech’s Jet Propulsion Center, confers with his lawyer, Grant B. Cooper, during his deportation hearing on Nov. 16, 1950. Photo: Bettmann Archive/Getty Images

Tsien’s story might have served as a lesson in how suspicion and surveillance can create unnecessary problems. But for Hoover’s FBI, his contributions to Chinese defense technology justified escalated surveillance. Eleven days after China’s 1967 weapons test, a memorandum from the FBI director’s office arrived in field offices around the country. “The recent detonation of a hydrogen bomb, far ahead of the time the Western intelligence community anticipated China would have such capability, highlights the fact that covert collection of information is undoubtedly going on,” the memo read. That China’s weapons knowledge was stolen was not, in fact, a foregone conclusion. Before it severed relations with Beijing in 1960, the Soviet Union had provided critical weapons assistance, and the Chinese nuclear weapons project included a number of skilled scientists besides Tsien. But Hoover suspected espionage — and he had a target group in mind. He warned in a 1966 article of the danger of “persons who have strong ties to the Orient,” particularly “students and scientists with living relatives behind the Bamboo Curtain.” The 1967 internal FBI memo, which referred to Chinese Communists as “Chicoms,” echoed this sentiment. “While it is known that numerous Western-trained scientists, particularly Chinese from U.S., have returned to China and have the training and ability to accomplish a nuclear program,” the memo said, “the Chicoms must keep up to date on technological advances in the West in order to create the finished product. We have long suspected that Chicom collection of needed information is accomplished through contacts with ethnic Chinese scientists and technicians in this country.” A later program document was more direct, warning bluntly of “the problem of Chinese scientists” in the United States.

Like Sheng, many ethnic Chinese students and scientists in America at the time had emigrated before the 1949 revolution. Others had come from Taiwan and Hong Kong, meaning that they were probably not diehard Communists. But the FBI suspected, citing a confidential source, that scientific secrets were passed to the Chinese government through “networks operating among Chinese communities in this country.” To combat this imagined drain of information, Hoover’s office proposed compiling lists of ethnic Chinese researchers and students — including U.S. citizens — and placing them under surveillance. An internal FBI letter sent on September 28, 1967, recommended that “an index be maintained in the Chinese Unit of Nationalities Intelligence Section regarding ethnic Chinese scientists in the U.S.” in order to create “a central repository of information” on these individuals. The letter suggested compiling three-by-five index cards listing the profession, clearance level, background, and “degree of cooperation” of each scientist and keeping the cards in a locked drawer. The writer estimated that five people could be added to the index every week. FBI leadership believed that there were 4,000 ethnic Chinese scientists with advanced degrees working in U.S. universities and industry at the time. (The actual figure may have been higher.)

The documents show both that the FBI cast a wide net and that it struggled to come up with useful lists. One document made clear that the bureau aimed to identify U.S. citizens of Chinese descent, not just Chinese nationals. The director’s office recommended working off the membership records of the Chinese Association of Scientific Workers, an organization that had ties to the Chinese Communist Party but had disbanded 17 years earlier. “They didn’t have any overall information on Chinese scientists in the U.S.,” said Wang, the scholar of U.S.-China relations in the Cold War era, “so the best they could come up with was that 1950 list.”

One FBI special agent in charge noted in a response to the director’s office that there were some 2,000 ethnic Chinese students in the New York area alone. Foreign student advisers might help identify the most relevant targets, he wrote, but they might not cooperate on such “a sensitive area of inquiry,” adding that “conceivably such data could not be obtained directly from certain schools.” It was the late 1960s; few people in academia were inclined to cooperate with the FBI. The agent suggested asking defense contractors for lists of ethnic Chinese employees.

Nonetheless, the New York field office opened as many as 200 files on ethnic Chinese students in technical fields. San Francisco opened as many as 75 files. Cincinnati and Seattle responded as well. The program documents include several names of targeted individuals, as well as general descriptions of specific targets, like “a graduate student” and “a Chinese engineer at Boeing.” Hoover’s office ordered the file of Tsien Hsue-Shen reopened, and the FBI tracked people with even tenuous connections to the rocket scientist, including his friends’ relatives. One person monitored under the program was an MIT professor from Indonesia — a target, presumably, because he was of Chinese ethnicity. It is unclear from the documents whether the Chinese scientist program started in 1967 or simply accelerated after the hydrogen bomb test. Sheng first drew the FBI’s notice in 1965, when, according to his file, “he made numerous allegations, both of a criminal and security nature, concerning a former friend who owed him a large sum of money.” (His file does not specify, but Liu believes that these allegations were made to local police.) In any case, by 1967, some agents had ambitious goals for the project. The special agent in charge of the San Francisco office suggested recruiting ethnic Chinese scientists as potential double agents. This plan involved planting researchers in critical laboratories, then waiting until Chinese intelligence operatives approached them. Whether the plan was broadly executed or produced useful intelligence is unknown, but at least one Chinese American scientist from the era reported being tasked with spy work. As a physicist at Johns Hopkins University’s Applied Physics Laboratory, Chih-Kung Jen often attended international conferences. In his memoir, Jen recalled that ahead of a conference in Tokyo in the late 1960s, a representative from an unnamed agency came to his office and tried to persuade him to spy on a mainland scientist whom Jen considered a friend. “According to his plan, I was to look for a man seated in an airport waiting chair reading a particular newspaper, and to approach this man calling him by the name of ‘Mr. Winston,’ after which I would receive further instructions,” Jen wrote. After the agent concluded his explanation, he pulled out a checkbook, tore off a blank check, and handed it to Jen in an apparent effort to buy the physicist’s cooperation. The offer made Jen furious. He insisted that the man get out of his office.

A fter Nixon’s historic visit to China, the Chinese scientist program continued. As Chinese American scientists returned to visit long-lost friends and relatives, the bureau closely tracked them. In 1972, Jen led a delegation of Chinese American scientists and their families to China. Katherine Yih, who joined her father on the trip, recalled a highly orchestrated tour that included visiting agricultural communes and watching children’s dance performances. “We were being shown the successes of the revolution,” she said. The visitors were seen as important enough that they were also taken to meet Premier Zhou Enlai, a development that almost certainly heightened the suspicions of U.S. counterintelligence operatives. Jen held a U.S. government security clearance but did not work with classified material. After the trip, his FBI file reveals, the bureau monitored the phone numbers he called, as well as how long he stayed on the phone for each conversation. The file also describes efforts to ascertain his loyalty to the United States.

According to a 1975 document listing all domestic FBI counterintelligence programs, the Chinese scientist program was focused on recruiting scientists as assets. Paul Moore, a former FBI China analyst who started at the bureau in the late 1970s, explained the program in an interview as an attempt to work counterintelligence in a difficult situation. “The guys in the Chinese squad had to do something, so what were they going to do? There wasn’t any Chinese diplomatic establishment, China was thousands of miles away, and they didn’t want to say, ‘We’re not doing anything about China.’ So what’s left? You’ve got the well-educated Chinese, and you’ve got the Chinese coming into the country illegally.” Moore told me that he believed the program was scrapped in the late 1970s. The last document clearly connected to the Chinese scientist program that I could find was from 1978. But the surveillance of Chang-Lin Tien, the professor of mechanical engineering at UC Berkeley who later became the university’s chancellor, continued into the 1980s. His FBI file, published in 2012 by the Daily Californian, shows that agents followed him to art openings, pulled his credit reports, and called hotels he had booked to make sure he checked in. (The bureau also tried, unsuccessfully, to recruit him as an informant.) A gregarious man who once led a conga line at the wedding of two of his students, Tien enjoyed hosting visitors from around the world and believed in building ties with China. But he made clear that he saw the FBI’s efforts as harassment. “He expressed his belief that the FBI was continuing to harass Chinese academicians like himself just as was done during the 1950s,” according to a note in his file.

Chang-Lin Tien, chancellor of the University of California at Berkeley, in 1990 on the Berkeley campus. Photo: Kristy MacDonald/AP

Melany Hunt, a scientist who was a Ph.D. student in Tien’s lab in the 1980s, said that the work she and others conducted there was all basic research. “My grandfather always believed cooperation in the sciences could play a key role in promoting peace between the U.S. and China,” Tien’s granddaughter, Kylie Tien, told me. “That aspiration put him under the scrutiny of a program launched at a time in history where fear and suspicion heavily impacted our government’s actions.” In 1996, Tien appeared on President Bill Clinton’s shortlist for secretary of energy. The post would have made him the first-ever Asian American cabinet secretary. But he became an undeserving casualty in the “Chinagate” campaign finance scandal, an alleged effort by China to influence U.S. politics, and was abruptly dropped as a candidate. (Clinton later appointed him to the National Science Foundation board.) The logic underlying the Chinese scientist program drove FBI investigations for years. In 1995, history repeated itself when a defector claiming to have worked on China’s weapons program turned up at the offices of Taiwan’s internal security service, carrying documents indicating that China had some knowledge of the United States’s W88 warhead. As in 1967, some in Washington suspected foul play. The only possible explanation, they concluded, was that China had stolen weapons secrets from the United States. Deciding that the leak must have come from Los Alamos National Laboratory, Department of Energy investigators went in search of a suspect. The FBI was enlisted to help. The bureau codenamed the inquiry Kindred Spirit, after China’s assumed tendency to target ethnic Chinese. Investigators homed in on ethnic Chinese researchers who had worked in any way on the development of the warhead. They soon found a suspect in a longtime Los Alamos scientist: Wen Ho Lee. In a strange twist, Lee’s wife Sylvia, had reportedly acted as an asset for the FBI and CIA in the 1980s. Now they were on the other side. Before Lee could be formally charged, someone leaked his name to the New York Times, which outed him as a suspect in March 1999. To justify searching Lee’s home, the FBI submitted an affidavit that used language drawn from Hoover’s playbook, noting that “People’s Republic of China intelligence operations virtually always target overseas ethnic Chinese with access to intelligence information sought by the PRC.” Lee was arrested in December 1999 and held in solitary confinement 23 hours a day in a New Mexico jail for the better part of a year. Eventually, the case against Lee unraveled and in September 2000, he was acquitted of 58 of the 59 charges against him. He pleaded guilty to a single felony count of mishandling classified information. In 2006, Lee won a $1.6 million settlement from the U.S. government and five media organizations.

Former Los Alamos nuclear scientist Wen Ho Lee, right, addresses media outside the Federal Courthouse in Albuquerque, N.M., on Sept. 13, 2000, after he was freed from nine months of solitary confinement. Photo: Mike Fiala/AFP via Getty Images

The Lee debacle prompted a congressional investigation and sparked a national conversation. Nonetheless, stereotyping and bad analysis endured within the FBI. Moore, the former analyst, popularized a theory known as “a thousand grains of sand,” which held that China relied on a “human wave” of ethnic Chinese intelligence collectors to pursue bits of information that the government then pieced together. “The myth that Chinese Americans are more susceptible to becoming Chinese agents is persistent,” said former FBI agent Michael German, a fellow with the Brennan Center for Justice’s Liberty and National Security Program. He compared it to the tendency in counterterrorism work to blur “important distinctions between nationality, sects, or ambitions of different groups into one Muslim radicalism.” He added: “Prioritizing national security augurs this kind of bias.” The same bias extends to the treatment of Chinese American FBI employees, critics say. Despite efforts from FBI leadership to diversify the bureau’s staff and calls from community organizations to increase representation of people of color, Asian Americans now make up only about 4 percent of agents. A former FBI supervisor whom I’ll call Don Lieu told me that in a routine security check, his unit’s embedded security officer asked him whether he hung Chinese lanterns in his home and whether he was friendly with people who were “in touch with Chinese culture.” (Lieu asked me to identify him by his grandfather’s first name and a family surname, citing concerns about retaliation.) Another time, he said, a security officer brought up the fact that Lieu dated Asian Americans. Lieu, who grew up in the New York City area, said he responded, “I can guarantee that none of these women are foreign nationals. In some cases, they are multigeneration Americans like myself.” He told me that the security officer then questioned how he could be sure that a girlfriend was a U.S. citizen, suggesting that any “close and continuing contact” with a Chinese American woman put the United States at risk. Lieu told me that in his view, institutional racism, not individual bias, is to blame for these encounters. “Most of the people who are doing the investigations are just following the guidance of the top boss,” he said. “Everything is coming down, and they’re just getting their marching orders to do this.” The message from leadership, he said, is that “Chinese Americans are being weaponized as a tool by foreign nationals.” FBI training materials obtained by the American Civil Liberties Union under the Freedom of Information Act in 2012 reveal approaches that are at best inadequate and at worst offensive. One presentation is sourced from “The Idiot’s Guide” — presumably “The Complete Idiot’s Guide to Modern China” — and titled “The Chinese.” “Imagine trying to explain the behavior of Americans and titling a slide presentation ‘The Americans,’” said German. “‘This is what the Americans are like.’ It would be absurd. It’s just mind-numbingly stupid to put on a presentation like that.” Another presentation given by the FBI’s Behavioral Science Unit, according to the documents obtained in 2012, deals with group-focused cultures, defined as Arabs, Iranians, Koreans, and Chinese. “Never attempt to shake hands with an Asian; never stare at an Asian,” the presentation warns. It also contains an offhand reference to “somatization” — the tendency to experience emotional distress as physical pain. The slide offers no explanation, but this idea has been used to suggest that Chinese culture is psychologically immature. Harry Sheng was an early victim of FBI discrimination. Throughout the 1970s, he kept trying to figure out why his life in the United States had changed so radically after his visit to China. “I contributed my best knowledge to the U.S. defense work,” he wrote his congressperson, Milton Robert Carr of Michigan, in 1975. “I will continue to fight until the truth comes out.” When Carr asked the FBI for details, the bureau replied in a letter: “FBI files contain no derogatory information on Mr. Sheng.” In 1977, Sheng applied for a new passport, explaining that he wanted to visit his mother again. Later in the year, he corresponded with a source whom the FBI considered suspicious — the person’s name is redacted — and submitted a FOIA request for his FBI file. In response, the FBI pulled his driver’s license and bank and income tax records and followed him around Michigan. By then, Sheng could find only temporary jobs. He started a stint at McGraw-Edison, which manufactured heating and air-conditioning units. The FBI monitored his residence and tailed his red Volkswagen as he drove from his home to work one morning at 7:15 a.m., according to a report that appears in his FBI file.

Thirteen years had passed since Sheng had first appeared on the FBI’s radar. He still had no explanation for why he was being watched. A few months later, a confidential memo from the Detroit field office to the director’s office stated that there was no “security risk on the part of the subject.” The memo concluded: “Detroit is recommending he not be reinterviewed and is closing this file.”