In an extraordinary public rebuke, Cahalan denounced the verdict as a “miscarriage of justice” brought on by Cockrel’s rank appeals to “racial emotions.” Cockrel immediately fired back. “Cahalan is a classic example of those who applaud the system when it produces what they want, but go crazy when their own ox gets gored,” he said. “Persons who never had a word of criticism when all-white juries were sending black people, Puerto Ricans, and white working-class people to Jackson [a Michigan prison] are suddenly now becoming concerned and are threatening the abolition of the jury system.” Sixty-one local lawyers, all of them white, agreed with Cockrel, signing a petition that urged Cahalan “to stop attacking judges, defense attorneys, juries, and witnesses.” To drive home Cahalan’s double standard, Cockrel pointed out that there had never been a homicide conviction in Detroit of a white police officer for the killing of a black man. “The police,” he said mischievously, “must not countenance mad dog killers among their ranks.”

But Detroit wasn’t done putting STRESS on trial. Not long after Raymond Peterson shot and killed Robert Hoyt, he shrugged off the murder. “I don’t like taking another man’s life,” he told the Detroit Free Press, “but it seems that I am a magnet for trouble.” Peterson claimed self-defense, a difficult proposition to disprove before the era of dashboard cameras and smartphone videos. But by planting a knife on Hoyt, Mr. STRESS had slipped up: Forensic investigators, examining the knife, discovered hairs matching Peterson’s pet cat. He was arrested and charged with second-degree murder.

His trial began in February 1974. Selection of the jury, which included just two blacks, took 17 days. Peterson wore a bulletproof vest to court, and fellow STRESS officers packed the room in support. His partner, Gary Prochorow, testified that Hoyt had been driving at 100 miles per hour and that he’d been convinced the autoworker “was going to kill us both.”

Over two days of testimony, Peterson never denied shooting Hoyt or planting the knife. Instead, he insisted that his notoriety as Mr. STRESS had left him in “constant fear for his life,” and that he had received numerous death threats. His lawyer, Norman Lippitt, argued that the warping influence of STRESS had driven his client, almost inexorably, to murder. Peterson, he said, had been merely “acting as he was trained.” The system itself, not the officer, was to blame:

He was educated to respect law and order and to take orders. He was conditioned by the cruelty in the streets of this city, by the hate that permeates the very air we breathe. He was given a gun by an ignorant bureaucracy, and when he used it with fatal results, was lauded and praised by his narrow-minded, nonthinking superiors. The very men he was taught to respect and obey are the men who encouraged him and led him to this day.... A dead hold-up man is considered an accomplishment. Officers who kill them are congratulated, lauded, and given medals.

On February 27, Peterson was acquitted. Outside the court, he told reporters that he planned to celebrate with a vacation in Mexico. He was awarded $45,728 in back disability payments and allowed to retire with his full pension.

Before killing Hoyt, Peterson once asked a reporter, “What’s racism? You don’t like black people? You don’t like Polacks? I’m a Polack. I don’t take offense. My wife’s a Mick. What the hell’s a racist? A racist is something someone just wants to start an argument about. I don’t see why we all can’t just get together, black, white, yellow, striped, or purple. Our common problem is the world. If we don’t get together and do something about it, it’s going to go down the drain.”

While he was on trial for killing Hoyt, Peterson lost 50 pounds and acquired a heavy drinking habit. Two years later, he sat for a final interview with the Detroit Free Press. Reporter Tom Ricke described Peterson as a “haunted man” who spoke in a nearly inaudible whisper and detailed symptoms that, today, might result in a diagnosis of post-traumatic stress disorder. Working for STRESS had left him confused, psychologically scarred, perpetually afraid. “I pay for it every day,” Peterson said. “I’ll be paying for it the rest of my life, for what the hell happened.”

In September 1973, two months after his own acquittal, Hayward Brown was arrested and beaten by three plainclothes STRESS officers during a traffic stop. The cops insisted they hadn’t been following Brown, although one of them, Donald Lewis, had been working backup with officers Bradford and Dooley on the night Bradford was killed. They had only stopped the car, they said, after they spotted Brown toss an envelope of what they believed to be narcotics out of the passenger-side window.

The powder in the envelope they claimed to recover turned out to be quinine, which can be used to cut heroin. The STRESS team also claimed to have found heroin in Brown’s sock and marijuana in his jacket pocket, as well as a handgun. On the ride to the police station, the STRESS team said Brown, while handcuffed in the backseat, reared up and kicked one of them in the back of the head, forcing them to pull over the squad car and use force to restrain him. Lewis and one of the other officers admitted to hitting Brown with their flashlights; the third officer said he used his hands. No mention of Brown resisting arrest, or of the officers striking him back, made it into the initial police report, though Brown was eventually taken to a hospital emergency room. The driver of Brown’s car, a woman named Bonita Burton, was not arrested.

In Brown’s version of events, the officers drove him to Detroit’s heavily forested, nearly 300-acre Palmer Park and beat him savagely. News reports described him as “barely ambulatory” when the officers dropped him at the hospital. He had to be helped up the steps, and his mother said he was unable to turn himself over in his hospital bed; bruises covered his head and stomach, and his entire right arm was soaked in blood. Cockrel said the officers had meant to kill Brown but somehow “messed it up.” STRESS commander Bannon defended his men, astonishingly, by pointing out that they “hadn’t been that inefficient in the past.” They could have easily killed Brown, he argued, had they intended to do so.

Despite the beating, Brown was charged with illegal possession of narcotics and a firearm. A jury freed him after deliberating for five minutes.

Not long after his fourth acquittal, Brown went to live with relatives in the Compton neighborhood of Los Angeles. But he was forced to return to Detroit in April 1974, when he was indicted by a federal grand jury for the firebombing of the Planned Parenthood clinic. (In an ironic twist, the federal charges against Brown, which would have appealed to the average law-and-order conservative of the time, were only possible thanks to Planned Parenthood’s federal funding.) Because the trial was taking place in a U.S. district court, the jury would be drawn from the suburbs as well as the city, and wound up including only four black jurors. Judge Cornelia Kennedy, a Nixon appointee, further stacked the deck against Brown by ruling that his “confession” to the firebombing in the backseat of the squad car was admissible.

On January 27, 1975, the jury found Brown guilty of the firebombing and he was sentenced to eight years in prison. Freed on bond, he would be vindicated three years later, when an appeals court overturned the verdict, ruling the confession inadmissible. Once again, Brown was freed.

His life, however, remained dogged by brushes with the law, and a series of arrests ensued: in 1978, for carrying a concealed weapon; in 1979, for possession of heroin and stolen property; in 1980, for possession of narcotics, carrying a concealed weapon, and armed robbery. After one arrest, Brown attempted to hang himself in his jail cell, fashioning a noose from the belt of his sweater. The police officers on duty cut Brown down, claiming they had no idea of his identity—when he’d been arrested, he had given his name as Robert Johnson—and that, after being resuscitated, he had complained of being “tired of all the hassles, tired of being arrested.” Brown denied he’d attempted suicide, claiming the police had been the ones who tried to hang him.

Then, in March 1981, he was arrested again, for possession of heroin. This time, as the Free Press put it, his “nine-year winning streak” came to an end. An all-black jury found him guilty, and he was sentenced to up to four years in prison. In jail, his political views shifted. “I thought it was white people’s fault, totally,” he told a reporter. “Now I don’t think it’s a black and white thing. It’s economic and classes—you know, people trying to get over, and others fighting to hang on to what they have.”

Three years later, after completing his sentence, Brown was dead—shot during an apparent robbery. The only witness, a 52-year-old Detroit man named John Harris, claimed that two men had attempted to steal his jewelry at a dilapidated four-story apartment building known as a neighborhood drug den. When one of the would-be robbers flashed a blue-steel revolver, Harris said, he managed to grab Brown and use him as a human shield. The gunman shot them both and fled the scene in a brown Chevy Monte Carlo.

Harris was struck multiple times in the chest. Brown, pronounced dead on arrival at Henry Ford Hospital, had been shot point blank in the face and neck. Police found eight packets of a white powder and $800 in cash on Harris. Brown had a watch, lighter, set of keys, black notebook, and $4 in cash. Police speculated that it was a drug robbery gone wrong. “It seems clear that they were trying to rob Harris, but he surprised the robbers,” a police spokesman told reporters. “He looks like an old man, but he must have had a little more spunk than they thought. The old man was a little too bad for them.”

John Nichols, the police commissioner who conceived and launched STRESS, laughed out loud when he was informed of Brown’s death. “I think probably the violence of his career terminated in the kind of justice he richly deserved,” Nichols said. “Not too many Detroit police officers will be sorry to hear about it. At least, I’m not. Ultimately, justice does prevail.” A news report noted that “police headquarters was flooded with telephone calls from police officers, including some from officers vacationing in northern Michigan, asking if it were true that Brown was dead.”

When Melba Boyd heard the news of her cousin’s death, she flew back to Detroit from Germany, where she had been on a Fulbright sabbatical. “Hayward was always less angry than I was, because he was wise about things,” Boyd says. “He understood it was not going to go away after he was acquitted.” From the beginning, she says, Kenneth Cockrel had warned Brown that black people who won cases against the police often ended up dead. Boyd once asked her cousin how he had survived so many beatings. In such situations, he told her, the key was to protect your vital organs.

Cockrel warned Brown that black people who won cases against the police often ended up dead. “The brother never had a chance,” he said.

Chokwe Lumumba, who had represented Brown, spoke at his former client’s funeral. “We’re not talking about a monster here,” he reminded mourners. “We’re talking about a man.” To a reporter, he noted that Brown’s fight against STRESS made him a target. “The police were scrapping for revenge,” he said, “and Hayward walks the streets of Detroit, which are alive with crime. So if they see him near some crime, they will charge him…. His options there, like other options of young blacks, were destroyed. That left the streets.”

Cockrel, who had become one of the most outspoken members of the Detroit city council, expressed a similar sentiment about his former client. “The brother never had a chance,” he said. “His father was an autoworker and his mother was a hardworking, decent woman. But the brother was out there on the street, and the street is a stern mistress.”

Shortly after Brown’s initial series of acquittals, a state senator named Coleman Young was elected the first black mayor of Detroit. He had run for office on the promise that he would abolish STRESS and fire Commissioner Nichols—who also happened to be his Republican opponent in the mayor’s race. “Nowhere, perhaps, has the issue of police conduct in an age of high crime come to be so clearly focused as in Detroit,” The New York Times noted shortly before Young’s election.

In 1974, Detroit elected Coleman Young (right) as the city’s first African American mayor. Young promised to shut down STRESS, which was created by outgoing mayor Roman Gribbs (left), a former sheriff. Walther P. Reuther Library, Archives of Labor and Ubran Affairs, Wayne State University

True to his word, Young disbanded STRESS in 1974. The unit wound up costing the city more than $1 million in legal settlements. During its first year, STRESS was responsible for 90 percent of all killings by Detroit police officers. The final death toll, over the course of two and a half years, was 22. All but one of the victims were black. Over the same period, the unit conducted some 500 warrantless searches.

By the 1980s, crime in Detroit began soaring to new heights. But during the brief window between the end of STRESS and the onset of the crack cocaine epidemic, major crimes and murders both declined. A 1979 New York Times profile of Young called him “one of the most influential blacks in the United States,” and pointed out that not a single Detroit police officer had been killed in the line of duty in four years. By contrast, six officers had been killed in 1971, the first year of STRESS. (The article also admonished Young for being “occasionally uppity to whites both in public and in private.”)

Four decades after the trials of Raymond Peterson and Hayward Brown, those who fought to stop STRESS see little change in the tactics and mindset of many police departments, post-Ferguson. Kenneth Cockrel’s wife, Sheila, an activist who served on the Detroit city council, still has copies of a hand-drawn, mimeographed “cop-watching” manual that she distributed during the STRESS years to teach outraged citizens how to document police abuse with a Kodak 126 camera. “We knew the streets where people were being stopped,” she recalls, “and we’d get out and start taking pictures of the incidents.” Decades before the arrival of smartphones, cameras served as the first line of defense against billy clubs and police revolvers.

Cockrel views the resistance to STRESS and Black Lives Matter as part of the same arc of history. The video evidence of police misconduct that has emerged in recent years finally “provides the opportunity to unmask the lie that was told over and over again: ‘I thought he had a gun. I thought he had a knife. They came at me.’ I’ve been hearing these lies since I was 18 years old. And often, they’re lies told to cover up un-American behavior by police officers that’s racially based. What now happens for well-meaning people, particularly white people, watching this behavior unfold in front of their eyes, is that it puts them in the position of having to address what white privilege really means in this country. And that’s not a comfortable thing to do.”

Kenneth Cockrel, a persistent critic of Mayor Young from the left, remained skeptical of trying to “reform” the police. “Reformism is what is counterrevolutionary,” he said. “You do not write letters to attorney generals, meet with black police assistants, etc. You take over the police department and you take over the city.” Cockrel died of a heart attack in 1989. He was 50.

Raymond Peterson died in April of last year, at the age of 81. He still lived in River Rouge, a downriver suburb of Detroit. No media outlets seemed to take note of his passing, let alone his previous life as Mr. STRESS. In the final interview he granted, he admitted that he worried about the price he would pay for the people he killed. “What’s going to happen to me,” he wondered, “if there is a hereafter and I die and get up in front of the big boss and he says, ‘Hey, man, you were a little heavy on those people, weren’t you?’ ” He admitted to thinking at times, “You’re no better than a rotten murderer,” though his psychiatrists, he quickly added, always assured him, “No, man, it’s not the way you are—it’s the way you’ve been made.” He couldn’t seem to understand how a man like him, who had been raised “with a lot of love for everybody,” could end up “out on the street killing people, and it not really bothering me.”

“I’ll tell you,” he said. “If that ain’t sick, boy, I don’t know. I don’t know.”