When he finally read Wurst’s letter, however, he realized there was a catch. Even though Wurst had argued against it, the judge, Nicole Colbert-Botchway, had ordered him to wear an ankle monitor that would track his location at every moment using GPS. For as long as he would wear it, he would be required to pay $10 a day to a private company, Eastern Missouri Alternative Sentencing Services, or EMASS. Just to get the monitor attached, he would have to report to EMASS and pay $300 up front — enough to cover the first 25 days, plus a $50 installation fee.

White didn’t know how to find that kind of money. Before his arrest, he was earning minimum wage as a temp, wrapping up boxes of shampoo. His father was largely absent, and his mother, Lakisha Thompson, had recently lost her job as the housekeeping manager at a Holiday Inn. Raising Daehaun and his four siblings, she had struggled to keep up with the bills. The family bounced between houses and apartments in northern St. Louis County, where, as a result of Jim Crow redlining, most of the area’s black population lives. In 2014, they were living on Canfield Drive in Ferguson when Michael Brown was shot and killed there by a police officer. During the ensuing turmoil, Thompson moved the family to Green Bay, Wisconsin. White felt out of place. He was looked down on for his sagging pants, called the N-word when riding his bike. After six months, he moved back to St. Louis County on his own to live with three of his siblings and stepsiblings in a gray house with vinyl siding.

When White got home on the night of his release, he was so overwhelmed to see his family again that he forgot about the letter. He spent the next few days hanging out with his siblings, his mother, who had returned to Missouri earlier that year, and his girlfriend, Demetria, who was seven months pregnant. He didn’t report to EMASS.

What he didn’t realize was that he had failed to meet a deadline. Typically, defendants assigned to monitors must pay EMASS in person and have the device installed within 24 hours of their release from jail. Otherwise, they have to return to court to explain why they’ve violated the judge’s orders. White, however, wasn’t called back for a hearing. Instead, a week after he left the Workhouse, Colbert-Botchway issued a warrant for his arrest.

Three days later, a large group of police officers knocked on Thompson’s door, looking for information about an unrelated case, a robbery. White and his brother had been making dinner with their mother, and the officers asked them for identification. White’s name matched the warrant issued by Colbert-Botchway. “They didn’t tell me what the warrant was for,” he said. “Just that it was for a violation of my release.” He was taken downtown and held for transfer back to the Workhouse. “I kept saying to myself, ’Why am I locked up?’” he recalled.

The next morning, Thompson called the courthouse to find the answer. She learned that her son had been jailed over his failure to acquire and pay for his GPS monitor. To get him out, she needed to pay EMASS on his behalf.

This seemed absurd to her. When Daehaun was 13, she had worn an ankle monitor after violating probation for a minor theft, but the state hadn’t required her to cover the cost of her own supervision. “This is a 19-year-old coming out of the Workhouse,” she told me recently. “There’s no way he has $300 saved.” Thompson felt that the court was forcing her to choose between getting White out of jail and supporting the rest of her family.

Over the past half-century, the number of people behind bars in the United States jumped by more than 500%, to 2.2 million. This extraordinary rise, often attributed to decades of “tough on crime” policies and harsh sentencing laws, has ensured that even as crime rates have dropped since the 1990s, the number of people locked up and the average length of their stay have increased. According to the Bureau of Justice Statistics, the cost of keeping people in jails and prisons soared to $87 billion in 2015 from $19 billion in 1980, in current dollars.

In recent years, politicians on both sides of the aisle have joined criminal-justice reformers in recognizing mass incarceration as both a moral outrage and a fiscal sinkhole. As ankle bracelets have become compact and cost-effective, legislators have embraced them as an enlightened alternative. More than 125,000 people in the criminal-justice system were supervised with monitors in 2015, compared with just 53,000 people in 2005, according to the Pew Charitable Trusts. Although no current national tally is available, data from several cities — Austin, Texas; Indianapolis; Chicago; and San Francisco — show that this number continues to rise. Last December, the First Step Act, which includes provisions for home detention, was signed into law by President Donald Trump with support from the private prison giants GEO Group and CoreCivic. These corporations dominate the so-called community-corrections market — services such as day-reporting and electronic monitoring — that represents one of the fastest-growing revenue sectors of their industry.

By far the most decisive factor promoting the expansion of monitors is the financial one. The United States government pays for monitors for some of those in the federal criminal-justice system and for tens of thousands of immigrants supervised by Immigration and Customs Enforcement. But states and cities, which incur around 90% of the expenditures for jails and prisons, are increasingly passing the financial burden of the devices onto those who wear them. It costs St. Louis roughly $90 a day to detain a person awaiting trial in the Workhouse, where in 2017 the average stay was 291 days. When individuals pay EMASS $10 a day for their own supervision, it costs the city nothing. A 2014 study by NPR and the Brennan Center found that, with the exception of Hawaii, every state required people to pay at least part of the costs associated with GPS monitoring. Some probation offices and sheriffs run their own monitoring programs — renting the equipment from manufacturers, hiring staff and collecting fees directly from participants. Others have outsourced the supervision of defendants, parolees and probationers to private companies.

“There are a lot of judges who reflexively put people on monitors, without making much of a pretense of seriously weighing it at all,” said Chris Albin-Lackey, a senior legal adviser with Human Rights Watch who has researched private-supervision companies. “The limiting factor is the cost it might impose on the public, but when that expense is sourced out, even that minimal brake on judicial discretion goes out the window.”

Nowhere is the pressure to adopt monitors more pronounced than in places like St. Louis: cash-strapped municipalities with large populations of people awaiting trial. Nationwide on any given day, half a million people sit in crowded and expensive jails because, like Daehaun White, they cannot purchase their freedom.

As the movement to overhaul cash bail has challenged the constitutionality of jailing these defendants, judges and sheriffs have turned to monitors as an appealing substitute. In San Francisco, the number of people released from jail onto electronic monitors tripled after a 2018 ruling forced courts to release more defendants without bail. In Marion County, Indiana, where jail overcrowding is routine, roughly 5,000 defendants were put on monitors last year. “You would be hard-pressed to find bail-reform legislation in any state that does not include the possibility of electronic monitoring,” said Robin Steinberg, the chief executive of the Bail Project.

Yet like the system of wealth-based detention they are meant to help reform, ankle monitors often place poor people in special jeopardy. Across the country, defendants who have not been convicted of a crime are put on “offender funded” payment plans for monitors that sometimes cost more than their bail. And unlike bail, they don’t get the payment back, even if they’re found innocent. Although a federal survey shows that nearly 40% of Americans would have trouble finding $400 to cover an emergency, companies and courts routinely threaten to lock up defendants if they fall behind on payment. In Greenville, South Carolina, pretrial defendants can be sent back to jail when they fall three weeks behind on fees. (An officer for the Greenville County Detention Center defended this practice on the grounds that participants agree to the costs in advance.) In Mohave County, Arizona, pretrial defendants charged with sex offenses have faced rearrest if they fail to pay for their monitors, even if they prove that they can’t afford them. “We risk replacing an unjust cash-bail system,” Steinberg said, “with one just as unfair, inhumane and unnecessary.”

Many local judges, including in St. Louis, do not conduct hearings on a defendant’s ability to pay for private supervision before assigning them to it; those who do often overestimate poor people’s financial means. Without judicial oversight, defendants are vulnerable to private-supervision companies that set their own rates and charge interest when someone can’t pay up front. Some companies even give their employees bonuses for hitting collection targets.

It’s not only debt that can send defendants back to jail. People who may not otherwise be candidates for incarceration can be punished for breaking the lifestyle rules that come with the devices. A survey in California found that juveniles awaiting trial or on probation face especially difficult rules; in one county, juveniles on monitors were asked to follow more than 50 restrictions, including not participating “in any social activity.” For this reason, many advocates describe electronic monitoring as a “net-widener": Far from serving as an alternative to incarceration, it ends up sweeping more people into the system.

Dressed in a baggy yellow City of St. Louis Corrections shirt, White was walking to the van that would take him back to the Workhouse after his rearrest, when a guard called his name and handed him a bus ticket home. A few hours earlier, his mom had persuaded her sister to lend her the $300 that White owed EMASS. Wurst, his public defender, brought the receipt to court.

The next afternoon, White hitched a ride downtown to the EMASS office, where one of the company’s bond-compliance officers, Nick Buss, clipped a black box around his left ankle. Based in the majority white city of St. Charles, west of St. Louis, EMASS has several field offices throughout eastern Missouri. A former probation and parole officer, Michael Smith, founded the company in 1991 after Missouri became one of the first states to allow private companies to supervise some probationers. (Smith and other EMASS officials declined to comment for this story.)

The St. Louis area has made national headlines for its “offender funded” model of policing and punishment. Stricken by postindustrial decline and the 2008 financial crisis, its municipalities turned to their police departments and courts to make up for shortfalls in revenue. In 2015, the Ferguson Report by the United States Department of Justice put hard numbers to what black residents had long suspected: The police were targeting them with disproportionate arrests, traffic tickets and excessive fines.

EMASS may have saved the city some money, but it also created an extraordinary and arbitrary-seeming new expense for poor defendants. When cities cover the cost of monitoring, they often pay private contractors $2 to $3 a day for the same equipment and services for which EMASS charges defendants $10 a day. To come up with the money, EMASS clients told me, they had to find second jobs, take their children out of day care and cut into disability checks. Others hurried to plead guilty for no better reason than that being on probation was cheaper than paying for a monitor.

At the downtown office, White signed a contract stating that he would charge his monitor for an hour and a half each day and “report” to EMASS with $70 each week. He could shower, but was not to bathe or swim (the monitor is water-resistant, not waterproof). Interfering with the monitor’s functioning was a felony.

White assumed that GPS supervision would prove a minor annoyance. Instead, it was a constant burden. The box was bulky and the size of a fist, so he couldn’t hide it under his jeans. Whenever he left the house, people stared. There were snide comments ("nice bracelet") and cutting jokes. His brothers teased him about having a babysitter. “I’m nobody to watch,” he insisted.

The biggest problem was finding work. Confident and outgoing, White had never struggled to land jobs; after dropping out of high school in his junior year, he flipped burgers at McDonald’s and Steak ’n Shake. To pay for the monitor, he applied to be a custodian at Julia Davis Library, a cashier at Home Depot, a clerk at Menards. The conversation at Home Depot had gone especially well, White thought, until the interviewer casually asked what was on his leg.

To help improve his chances, he enrolled in Mission: St. Louis, a job-training center for people reentering society. One afternoon in January, he and a classmate role-played how to talk to potential employers about criminal charges. White didn’t know how much detail to go into. Should he tell interviewers that he was bringing his pregnant girlfriend some snacks when he was pulled over? He still isn’t sure, because a police officer came looking for him midway through the class. The battery on his monitor had died. The officer sent him home, and White missed the rest of the lesson.

With all of the restrictions and rules, keeping a job on a monitor can be as difficult as finding one. The hours for weekly check-ins at the downtown EMASS office — 1 p.m. to 6 p.m. on Tuesdays and Wednesdays, and 1 p.m. until 5 p.m. on Mondays — are inconvenient for those who work. In 2011, the National Institute of Justice surveyed 5,000 people on electronic monitors and found that 22% said they had been fired or asked to leave a job because of the device. Juawanna Caves, a young St. Louis native and mother of two, was placed on a monitor in December after being charged with unlawful use of a weapon. She said she stopped showing up to work as a housekeeper when her co-workers made her uncomfortable by asking questions and later lost a job at a nursing home because too many exceptions had to be made for her court dates and EMASS check-ins.

Perpetual surveillance also takes a mental toll. Nearly everyone I spoke to who wore a monitor described feeling trapped, as though they were serving a sentence before they had even gone to trial. White was never really sure about what he could or couldn’t do under supervision. In January, when his girlfriend had their daughter, Rylan, White left the hospital shortly after the birth, under the impression that he had a midnight curfew. Later that night, he let his monitor die so that he could sneak back before sunrise to see the baby again.

EMASS makes its money from defendants. But it gets its power over them from judges. It was in 2012 that the judges of the St. Louis court started to use the company’s services — which previously involved people on probation for misdemeanors — for defendants awaiting trial. Last year, the company supervised 239 defendants in the city of St. Louis on GPS monitors, according to numbers provided by EMASS to the court. The alliance with the courts gives the company not just a steady stream of business but a reliable means of recouping debts: Unlike, say, a credit-card company, which must file a civil suit to collect from overdue customers, EMASS can initiate criminal-court proceedings, threatening defendants with another stay in the Workhouse.

In early April, I visited Judge Rex Burlison in his chambers on the 10th floor of the St. Louis civil courts building. A few months earlier, Burlison, who has short gray hair and light blue eyes, had been elected by his peers as presiding judge, overseeing the city’s docket, budget and operations, including the contract with EMASS. It was one of the first warm days of the year, and from the office window I could see sunlight glimmering on the silver Gateway Arch.

I asked Burlison about the court’s philosophy for using pretrial GPS. He stressed that while each case was unique and subject to the judge’s discretion, monitoring was most commonly used for defendants who posed a flight risk, endangered public safety or had an alleged victim. Judges vary in how often they order defendants to wear monitors, and critics have attacked the inconsistency. Colbert-Botchway, the judge who put White on a monitor, regularly made pretrial GPS a condition of release, according to public defenders. (Colbert-Botchway declined to comment.) But another St. Louis city judge, David Roither, told me, “I really don’t use it very often because people here are too poor to pay for it.”

Whenever a defendant on a monitor violates a condition of release, whether related to payment or a curfew or something else, EMASS sends a letter to the court. Last year, Burlison said, the court received two to three letters a week from EMASS about violations. In response, the judge usually calls the defendant in for a hearing. As far as he knew, Burlison said, judges did not incarcerate people simply for failing to pay EMASS debts. “Why would you?” he asked me. When people were put back in jail, he said, there were always other factors at play, like the defendant’s missing a hearing, for instance. (Issuing a warrant for White’s arrest without a hearing, he acknowledged after looking at the docket, was not the court’s standard practice.)

The contract with EMASS allows the court to assign indigent defendants to the company to oversee “at no cost.” Yet neither Burlison nor any of the other current or former judges I spoke with recalled waiving fees when ordering someone to wear an ankle monitor. When I asked Burlison why he didn’t, he said that he was concerned that if he started to make exceptions on the basis of income, the company might stop providing ankle-monitoring services in St. Louis.

“People get arrested because of life choices,” Burlison said. “Whether they’re good for the charge or not, they’re still arrested and have to deal with it, and part of dealing with it is the finances.” To release defendants without monitors simply because they can’t afford the fee, he said, would be to disregard the safety of their victims or the community. “We can’t just release everybody because they’re poor,” he continued.

But many people in the Workhouse awaiting trial are poor. In January, civil rights groups filed suit against the city and the court, claiming that the St. Louis bail system violated the Constitution, in part by discriminating against those who can’t afford to post bail. That same month, the Missouri Supreme Court announced new rules that urged local courts to consider releasing defendants without monetary conditions and to waive fees for poor people placed on monitors. Shortly before the rules went into effect, on July 1, Burlison said that the city intends to shift the way ankle monitors are distributed and plans to establish a fund to help indigent defendants pay for their ankle bracelets. But he said he didn’t know how much money would be in the fund or whether it was temporary or permanent. The need for funding could grow quickly. The pending bail lawsuit has temporarily spurred the release of more defendants from custody, and as a result, public defenders say, the demand for monitors has increased.

Judges are anxious about what people released without posting bail might do once they get out. Several told me that monitors may ensure that the defendants return to court. Not unlike doctors who order a battery of tests for a mildly ill patient to avoid a potential malpractice suit, judges seem to view monitors as a precaution against their faces appearing on the front page of the newspaper. “Every judge’s fear is to let somebody out on recognizance and he commits murder, and then everyone asks, ’How in the hell was this person let out?’” said Robert Dierker, who served as a judge in St. Louis from 1986 to 2017 and now represents the city in the bail lawsuit. “But with GPS, you can say, ’Well, I have him on GPS, what else can I do?’”

Critics of monitors contend that their public-safety appeal is illusory: If defendants are intent on harming someone or skipping town, the bracelet, which can be easily removed with a pair of scissors, would not stop them. Studies showing that people tracked by GPS appear in court more reliably are scarce, and research about its effectiveness as a deterrent is inconclusive.

“The fundamental question is, What purpose is electronic monitoring serving?” said Blake Strode, the executive director of ArchCity Defenders, a nonprofit civil rights law firm in St. Louis that is one of several firms representing the plaintiffs in the bail lawsuit. “If the only purpose it’s serving is to make judges feel better because they don’t want to be on the hook if something goes wrong, then that’s not a sensible approach. We should not simply be monitoring for monitoring’s sake.”

Electronic monitoring was first conceived in the early 1960s by Ralph and Robert Gable, identical twins studying at Harvard under the psychologists Timothy Leary and B.F. Skinner, respectively. Influenced in part by Skinner’s theories of positive reinforcement, the Gables rigged up some surplus missile-tracking equipment to monitor teenagers on probation; those who showed up at the right places at the right times were rewarded with movie tickets, limo rides and other prizes.

Although this round-the-clock monitoring was intended as a tool for rehabilitation, observers and participants alike soon recognized its potential to enhance surveillance. All but two of the 16 volunteers in their initial study dropped out, finding the two bulky radio transmitters oppressive. “They felt like it was a prosthetic conscience, and who would want Mother all the time along with you?” Robert Gable told me. Psychology Today labeled the invention a “belt from Big Brother.”

The reality of electronic monitoring today is that Big Brother is watching some groups more than others. No national statistics are available on the racial breakdown of Americans wearing ankle monitors, but all indications suggest that mass supervision, like mass incarceration, disproportionately affects black people. In Cook County, Illinois, for instance, black people make up 24% of the population, and 67% of those on monitors. The sociologist Simone Browne has connected contemporary surveillance technologies like GPS monitors to America’s long history of controlling where black people live, move and work. In her 2015 book, “Dark Matters,” she traces the ways in which “surveillance is nothing new to black folks,” from the branding of enslaved people and the shackling of convict laborers to Jim Crow segregation and the home visits of welfare agencies. These historical inequities, Browne notes, influence where and on whom new tools like ankle monitors are imposed.

For some black families, including White’s, monitoring stretches across generations. Annette Taylor, the director of Ripple Effect, an advocacy group for prisoners and their families based in Champaign, Illinois, has seen her ex-husband, brother, son, nephew and sister’s husband wear ankle monitors over the years. She had to wear one herself, about a decade ago, she said, for driving with a suspended license. “You’re making people a prisoner of their home,” she told me. When her son was paroled and placed on house arrest, he couldn’t live with her, because he was forbidden to associate with people convicted of felonies, including his stepfather, who was also on house arrest.

Some people on monitors are further constrained by geographic restrictions — areas in the city or neighborhood that they can’t go without triggering an alarm. James Kilgore, a research scholar at the University of Illinois at Champaign-Urbana, has cautioned that these exclusionary zones could lead to “e-gentrification,” effectively keeping people out of more-prosperous neighborhoods. In 2016, after serving four years in prison for drug conspiracy, Bryan Otero wore a monitor as a condition of parole. He commuted from the Bronx to jobs at a restaurant and a department store in Manhattan, but he couldn’t visit his family or doctor because he was forbidden to enter a swath of Manhattan between 117th Street and 131st Street. “All my family and childhood friends live in that area,” he said. “I grew up there.”

Michelle Alexander, a legal scholar and columnist for The Times, has argued that monitoring engenders a new form of oppression under the guise of progress. In her 2010 book, “The New Jim Crow,” she wrote that the term “mass incarceration” should refer to the “system that locks people not only behind actual bars in actual prisons, but also behind virtual bars and virtual walls — walls that are invisible to the naked eye but function nearly as effectively as Jim Crow laws once did at locking people of color into a permanent second-class citizenship.”

As the cost of monitoring continues to fall, those who are required to submit to it may worry less about the expense and more about the intrusive surveillance. The devices, some of which are equipped with two-way microphones, can give corrections officials unprecedented access to the private lives not just of those monitored but also of their families and friends. GPS location data appeals to the police, who can use it to investigate crimes. Already the goal is both to track what individuals are doing and to anticipate what they might do next. BI Incorporated, an electronic-monitoring subsidiary of GEO Group, has the ability to assign risk scores to the behavioral patterns of those monitored, so that law enforcement can “address potential problems before they happen.” Judges leery of recidivism have begun to embrace risk-assessment tools. As a result, defendants who have yet to be convicted of an offense in court may be categorized by their future chances of reoffending.

The combination of GPS location data with other tracking technologies such as automatic license-plate readers represents an uncharted frontier for finer-grained surveillance. In some cities, police have concentrated these tools in neighborhoods of color. A CityLab investigation found that Baltimore police were more likely to deploy the Stingray — the controversial and secretive cellphone tracking technology — where African Americans lived. In the aftermath of Freddie Gray’s death in 2015, the police spied on Black Lives Matter protesters with face recognition technology. Given this pattern, the term “electronic monitoring” may soon refer not just to a specific piece of equipment but to an all-encompassing strategy.

If the evolution of the criminal-justice system is any guide, it is very likely that the ankle bracelet will go out of fashion. Some GPS monitoring vendors have already started to offer smartphone applications that verify someone’s location through voice and face recognition. These apps, with names like Smart-LINK and Shadowtrack, promise to be cheaper and more convenient than a boxy bracelet. They’re also less visible, mitigating the stigma and normalizing surveillance. While reducing the number of people in physical prison, these seductive applications could, paradoxically, increase its reach. For the nearly 4.5 million Americans on probation or parole, it is not difficult to imagine a virtual prison system as ubiquitous — and invasive — as Instagram or Facebook.

On Jan. 24, exactly three months after White had his monitor installed, his public defender successfully argued in court for its removal. His phone service had been shut off because he had fallen behind on the bill, so his mother told him the good news over video chat.

When White showed up to EMASS a few days later to have the ankle bracelet removed, he said, one of the company’s employees told him that he couldn’t take off his monitor until he paid his debt. White offered him the $35 in his wallet — all the money he had. It wasn’t enough. The employee explained that he needed to pay at least half of the $700 he owed. Somewhere in the contract he had signed months earlier, White had agreed to pay his full balance “at the time of removal.” But as White saw it, the court that had ordered the monitor’s installation was now ordering its removal. Didn’t that count?

“That’s the only thing that’s killing me,” White told me a few weeks later, in early March. “Why are you all not taking it off?” We were in his brother’s room, which, unlike White’s down the hall, had space for a wobbly chair. White sat on the bed, his head resting against the frame, while his brother sat on the other end by the TV, mumbling commands into a headset for the fantasy video game Fortnite. By then, the prosecutor had offered White two to three years of probation in exchange for a plea. (White is waiting to hear if he has been accepted into the city’s diversion program for “youthful offenders,” which would allow him to avoid pleading and wipe the charges from his record in a year.)

White was wearing a loosefitting Nike track jacket and red sweats that bunched up over the top of his monitor. He had recently stopped charging it, and so far, the police hadn’t come knocking. “I don’t even have to have it on,” he said, looking down at his ankle. “But without a job, I can’t get it taken off.” In the last few weeks, he had sold his laptop, his phone and his TV. That cash went to rent, food and his daughter, and what was left barely made a dent in what he owed EMASS.

It was a Monday — a check-in day — but he hadn’t been reporting for the past couple of weeks. He didn’t see the point; he didn’t have the money to get the monitor removed and the office was an hour away by bus. I offered him a ride.

EMASS check-ins take place in a three-story brick building with a low-slung facade draped in ivy. The office doesn’t take cash payments, and a Western Union is conveniently located next door. The other men in the waiting room were also wearing monitors. When it was White’s turn to check-in, Buss, the bond-compliance officer, unclipped the band from his ankle and threw the device into a bin, White said. He wasn’t sure why EMASS had now softened its approach, but his debts nonetheless remained.

Buss calculated the money White owed going back to November: $755, plus 10% annual interest. Over the next nine months, EMASS expected him to make monthly payments that would add up to $850 — more than the court had required for his bond. White looked at the receipt and shook his head. “I get in trouble for living,” he said as he walked out of the office. “For being me.”

Republished with permission under license from ProPublica, an investigative news agency.