A Fire in Minnesota. An Arrest in Mexico. Cameras Everywhere.

Mena Yousif wore dark clothing to the protest, with white sneakers and a blue hijab that she could pull over her face, perfect gear during a pandemic. Jose Felan, stocky and tall, wore a baseball cap and a gray T-shirt that showed off a distinctive tattoo on his forearm: “Mena,” with a crown above the “a.”

The couple had driven an hour north from Rochester to Minneapolis to join a crowd down the street from the State Capitol. It was three days after George Floyd had been killed by a white police officer; the couple was part of a growing protest movement that would send people into the streets across America to express their anger, frustration and pain over Mr. Floyd’s death.

Ms. Yousif, 22, had moved to Minnesota as a child, after her parents fled war-torn Iraq. She worked a series of retail jobs, including a stint at Chipotle, and was earning a business degree at a community college. Mr. Felan, 34, had bounced between Texas and Minnesota for most of his life, and had run afoul of the law in both places.

The unrest in Minneapolis had started to get destructive — that night, the National Guard would be called in — and the authorities would later allege in court filings that Mr. Felan was one of those to blame. He was carrying a thin white bag, sheer enough that, according to a criminal complaint, three canisters of diesel fuel were visible inside after he walked into a Napa Auto Parts store on University Avenue in St. Paul. Around 6 p.m., as captured on surveillance footage, he and Ms. Yousif entered a Goodwill next door and made their way into a back storage room where Mr. Felan allegedly took one of the diesel fuel canisters out of his bag, poured its contents onto a stack of cardboard boxes, and set them on fire.

Federal authorities assert that Mr. Felan also helped set fires at a school across the street and at a gas station, which were among over 1,500 buildings damaged that week. The surveillance footage from that day set off a nearly yearlong, international manhunt for the couple, involving multiple federal agencies and Mexican police. The pursuit also involved a facial recognition system made by a Chinese company that has been blacklisted by the U.S. government.

Ms. Yousif gave birth while on the run, and was separated from her baby for four months by the authorities. To prosecutors, the pursuit of Mr. Felan, who was charged with arson, and Ms. Yousif, who was charged with helping him flee, was a routine response to a case of property destruction. To fellow protesters, it’s part of an extreme crackdown on those who most fervently demonstrated against America’s criminal justice system.

But beyond the prosecutorial aftermath of the racial justice protests, the eight-month saga of a young Minnesota couple exposed an emerging global surveillance system that might one day find anyone, anywhere, the technology traveling easily over borders while civil liberties struggle to keep pace.

The Pursuit

A video of Jose Felan “went viral,” leading to “several tips, including from individuals who wish to remain anonymous,” an A.T.F. agent said.Credit…Bureau of Alcohol, Tobacco, Firearms and Explosives, St. Paul Field Division

As the political and corporate worlds wrestled with addressing racial injustice in America, and the events in Minneapolis overtook the Covid-19 crisis and the presidential campaign, the Bureau of Alcohol, Tobacco, Firearms and Explosives, or A.T.F., got to work trying to find the people who set fires.

The A.T.F., which is tasked with investigating arson cases, released photos of suspects, offering $5,000 for helpful tips from the public. A video of Mr. Felan “went viral,” leading to “several tips, including from individuals who wish to remain anonymous,” an A.T.F. agent said in a court document. (The A.T.F. has also used facial recognition technology, including the app Clearview AI, to identify unknown people, according to reporting from the Government Accountability Office and BuzzFeed.)

Mr. Felan and Ms. Yousif could not be reached for comment. Mr. Felan’s lawyer declined to comment as the case is pending, and Ms. Yousif’s lawyer did not respond to multiple attempts to reach him. This report is largely drawn from government documents and sources, and based on the account of their lives there, they were likely panicked. Mr. Felan had previous legal troubles.

And Ms. Yousif was approximately seven months pregnant.

So they drove, heading south on Interstate 35, a highway that runs down the middle of the country, stretching from Duluth, Minn., on Lake Superior, to Laredo, Texas, on the Mexican border. They had made their way through Iowa and just hit the northern part of Missouri, 300 miles from Rochester, when police first caught up with them.

A warrant had been issued for Mr. Felan’s arrest, allowing the authorities to ping his cellphone to locate him. According to a court document, late on a Monday night, more than a week after the events in St. Paul, local police in rural western Missouri, who were asked to go where the phone was pinging, stopped a black S.U.V. registered to Mr. Felan. Ms. Yousif was driving, and said she didn’t know where Mr. Felan was. The police let her go.

Ms. Yousif was then charged with helping Mr. Felan flee, and the A.T.F. put out a new request for help, setting the reward at $10,000: “We’re asking the public to be on the lookout for the couple along the Interstate 35 corridor.”

Over the next week, police kept pinging the location of Mr. Felan’s phone but kept missing him. According to a court document, he sent a message to his brother in Texas saying he was turning it off between messages, worried about being tracked; the couple eventually bought new phones.

They bore west, through Kansas and Oklahoma, making their way toward Mr. Felan’s family. His mother and brothers had heard about the manhunt and were sending one another worried Facebook messages. At some point, the couple exchanged cars with Mr. Felan’s mother.

Ms. Yousif’s family declined to speak in detail about what this experience has been like, and her life before she and Mr. Felan met in Minnesota and fell in love. Those who encountered Ms. Yousif as a college sophomore find the events of the past 14 months difficult to reconcile with the young woman they met in 2019. She had earned a scholarship from the American Business Women’s Association of Rochester and the woman who administered it remembered Ms. Yousif as mature and ambitious, wearing funky high heels, and chatting about her work as a bookkeeper for her father.

Ms. Yousif had dreams of starting her own business. She was on the dean’s list at Rochester Community and Technical College.

And then she was on the run.

On a Friday night in mid-June 2020, a surveillance camera at a Holiday Inn outside San Antonio captured Ms. Yousif and Mr. Felan driving his mother’s brown Toyota Camry into the hotel’s parking lot. They got out of the car, walked outside the view of the camera and then disappeared.

The A.T.F. increased its reward to $20,000 — $10,000 each for Mr. Felan, describing him as a “felon with multiple convictions,” and for Ms. Yousif, “his accomplice.” Mr. Felan faced a drug possession charge when he was 18 that led to an almost seven year prison sentence, and more recently, convictions for assault and for transporting undocumented immigrants near the Mexican border, for which he also spent time in prison.

The agency also released more images of them, including what appear to be their wedding photos, and warned that Ms. Yousif, “who appears to be noticeably pregnant, is known to have worn disguises while on the run, including wigs, hair extensions, hats and the absence of a hijab.”

Michael German, a former F.B.I. agent who is now a fellow at the Brennan Center for Justice, said the Justice Department under Attorney General William P. Barr was “very aggressively” seeking to make prosecutions from the George Floyd protests. “It wouldn’t surprise me that this case would have been a high-priority one,” he said.

Two weeks after officials lost track of the couple, a deputy U.S. marshal told a Texas news station that the authorities suspected they were trying to get to Mexico.

“Mena is, we believe to be, between six to eight months pregnant. We’re also taking that into consideration in our investigation,” he said. “The fact that there is an unborn child, an innocent child here involved, as well, at this point, the quicker all of this ends, for everybody’s sake, the better.”

That “innocent child” would later be separated from his parents or any family member for more than four months.

Blacklisted Technology

The photo projected on the screen in the conference room leapt out at him, of a woman against a pale blue background, wearing bright red lipstick and a beige hijab. Her name was next to the photo: Mena Yousif. Federico Pérez Villoro, an investigative journalist and artist based in Mexico City, wrote the name down so he could figure out who she was.

Mr. Villoro was meeting with law enforcement officials in Coahuila, Mexico last year; they were demonstrating their new equipment: facial recognition software and nearly 1,300 cameras from a Chinese company called Dahua Technology.

A group of police officers and a government employee in charge of Mexico’s first large-scale facial recognition system, Luis Campos, were explaining how the new $30 million system could flag a face so that police would get an alert in real-time if a camera spotted that person.

The authorities in Coahuila, a state that borders Texas, had bought the system in 2019; in the months since it was installed, they had searched for only about 100 people, said Mr. Campos, and he projected a few of their faces on the screen, including those of Ms. Yousif and Mr. Felan.

Mr. Campos told Mr. Villoro that the F.B.I. had learned about Coahuila’s system and asked for help finding people accused of terrorism. Mr. Villoro did his own research after the meeting.

“They were anti-racist protesters and not being searched for ‘terrorism’ in the U.S. but for acts of vandalism,” Mr. Villoro said. He was disturbed to see the technology being used that way, and mentioned it in his article. “They just said that the F.B.I. had called Sonia Villarreal, Coahuila’s secretary of public security, with the request, a sort of informal favor, it seemed.”

Mr. German, the former F.B.I. agent who now studies civil liberty issues, said that the F.B.I. had a long history of categorizing civil disobedience as terrorism, and that the agency would likely view arson during a protest as a terrorism case. “Lighting any kind of fire at a protest is not something that’s going to be helpful to you in the eyes of the law,” he said. Mr. German also said it would not be unusual for the agency to seek help from Mexican authorities to find the couple. “There is a tremendous amount of cooperation with Mexican law enforcement on a host of law enforcement issues,” he said.

Part of what bothered Mr. Villoro was that the company that made the surveillance system, Dahua, had been blacklisted by the U.S. government in 2019. Dahua, based in Hangzhou, is one of the largest video surveillance companies in the world; it is partly state-owned, but also publicly traded, with revenues of $27 billion last year. Under the Trump administration, both the Commerce and Defense departments put Dahua on blacklists as the trade war with China escalated, and as scrutiny increased on human rights abuses against Muslims in China’s Xinjiang region.

According to a notice in the Federal Register, Dahua’s products were used in “China’s campaign of repression, mass arbitrary detention and high-technology surveillance” against Uighurs and other Muslim minority groups. As a result, the U.S. government cannot use its products and Dahua cannot buy American goods. (American individuals and businesses still can though; Amazon bought its thermal cameras last year to help detect Covid-19 symptoms at its warehouses.)

“Dahua Technology flatly denies the allegations,” the company said in a statement about the blacklist. “Ultimately, no security solutions company can fully control how its technologies are used by end users.”

Federal authorities declined to comment on the use of facial recognition technology in the pursuit of Mr. Felan and Ms. Yousif. “We ask for assistance with fugitive investigations from other countries every day and cannot direct which sources and methodologies they may employ to assist in fugitive investigations,” said Lynzey Donahue, spokeswoman for the U.S. Marshals.

“I have not heard of a story like this before where our government asked another government to do face recognition for it,” said Adam Schwartz, a surveillance lawyer at the Electronic Frontier Foundation. “It’s very upsetting.”

The cutting-edge system was in use, searching for signs of the couple in Mexico, but it does not appear to be what led authorities to them. A spokeswoman for the ATF said the agency paid the $20,000 to someone who had information on the couple. “That was then used to locate Felan and Yousif while in Mexico, directly leading to their apprehension,” said Ashlee J. L. Sherrill, the spokeswoman.

In his article, Mr. Villoro deemed the real-time facial recognition system both an abuse of civil liberties and a technological failure that hadn’t lived up to its promise. But the technology is spreading globally, in part because China is aggressively marketing it abroad as part of the country’s “Belt and Road” initiative, said Marc Rotenberg, president of the Center for A.I. and Digital Policy, a nonprofit in Washington.

China is marketing mass surveillance technology to its trading partners in Africa, Asia and South America, he explained, pitching it as a way to minimize crime and promote public order in major metropolitan areas.

“I don’t think they particularly see it as evil,” Mr. Rotenberg said.

In the United States, facial recognition technology is widely used by law enforcement officials, though poorly regulated. During a congressional hearing in July, lawmakers expressed surprise that 20 federal agencies were using it without having fully assessed the risks of misuse or bias — some algorithms have been found to work less accurately on women and people of color, and it has led to mistaken arrests. The technology can be a powerful and effective crime-solving tool, though, placing it, for now, at a tipping point.

At the start of the hearing, Representative Sheila Jackson Lee, Democrat of Texas, highlighted the challenge for Congress — or anyone — in determining the benefits and downsides to using facial recognition: It’s not clear how well it works or how widely it’s used. As Ms. Jackson Lee said, “Information on how law enforcement agencies have adopted facial recognition technology remains underreported or nonexistent.”

The Arrest

After crossing into Mexico last summer, Mr. Felan and Ms. Yousif evaded capture for months, long enough for their son to be born there.

This February, however, the day after Valentine’s Day, they were arrested in Puerto Vallarta, a tourist destination on the Pacific coast, 800 miles south of the U.S. border.

“Thanks to the skilled investigative work of the A.T.F. and the tireless apprehension efforts of the U.S. Marshals Service, these two defendants, who have been on the run for more than eight months, will be returned to Minnesota to face justice,” U.S. Attorney Erica H. MacDonald said in a statement.

Mr. Felan and Mr. Yousif were transported to San Diego, where they were charged in federal court — three counts of arson for Mr. Felan, which carries a possible prison sentence of 20 years, and two counts of accessory after the fact for Ms. Yousif, with a maximum penalty of 10 years in prison.

They are now back in Minnesota, forbidden from talking to each other while they await federal prosecution.

But their six-month-old son did not travel to the United States with them; he was taken into custody by Mexican authorities when the couple was arrested and placed in an “international orphanage,” according to Youser Yousif, Mena’s sister, because he was not considered a U.S. citizen. When a child is born abroad, the birth has to be registered with a U.S. embassy or consulate, but that is hard to do when on the run from the law. Youser Yousif said her sister had been filling out paperwork for months trying to secure the return of her son.

In June, four months after the child was taken from his parents, Mena Yousif’s family traveled to Mexico to try to retrieve him. Ms. Yousif’s lawyer filed a request for the release of her passport, which had been seized by the authorities, so it could be sent to her parents in Mexico “to prove that the mother of the child is a U.S. citizen.”

The judge agreed to the request and ordered Ms. Yousif’s probation officer to mail the passport to Mexico.

“The U.S. Marshals went to great lengths to ensure that the apprehension of this couple was handled in such a way that the child could be placed in the custody of family members,” said Ms. Donahue, spokeswoman for the U.S. Marshals.

The Fallout

Surveillance footage and smartphone cameras provided the evidence that investigators needed to look into over 100 cases of arson from the three days of unrest in Minneapolis. A handful of people who have been convicted so far face up to four years in prison, and have been ordered to pay millions of dollars in restitution.

Video evidence was crucial, too, in the event that set off the unrest, the murder of George Floyd. It’s how the world knew what had happened to Mr. Floyd, and why Derek Chauvin, the officer who knelt on his neck, was sentenced to 22 years in prison for killing him.

We are living in a world where tracking technologies, from surveillance cameras to our smartphones, are recording more and more of our lives, raising urgent questions about the extent to which those recordings should feed into surveillance systems, and how easy we want it to be for governments and companies to track us in real time.

In a 2019 report on video analytics, the American Civil Liberties Union argued that millions of surveillance cameras installed in recent decades are “waking up” thanks to automation, such as facial recognition technology, which allows them to not just record, but to analyze what is happening and flag what they see: “That will usher in something entirely new in the history of humanity: a society where everyone’s public movements and behavior are subject to constant and comprehensive evaluation and judgment by agents of authority — in short, a society where everyone is watched.”

In this case, U.S. citizens were subject to a real-time tracking system that the U.S. government itself had deemed abusive in China.

“Real-time face recognition systems are dangerous now and threaten to become even more pervasive and all-encompassing,” said Ashley Gorski, a lawyer at the A.C.L.U. “The claimed benefits to law enforcement should not obscure the privacy harms for millions of people subject to these proliferating systems and government monitoring of their everyday movements.”

Mr. Felan is awaiting trial in Sherburne County jail on the outskirts of Minneapolis, while Ms. Yousif is on house arrest at her parents’ home in Rochester. A community group assisting people arrested as a result of the protests posted a message from Mr. Felan on its Facebook page: “This is the most difficult time I’ve ever had to go through in my entire life.”

Natalie Kitroeff, Oscar Lopez and Paul Mozur contributed reporting. Susan C. Beachy contributed research.