Michael A. Cox, Sr., was laser-focused on the suspect running away from him. It was a freezing night in January 1995, and Cox—with a phalanx of fellow Boston police officers behind him—was chasing a car of homicide suspects through the streets of Dorchester and Mattapan and into a cul-de-sac that ended at a fence.

Cox’s target jumped the fence and kept running. Cox, a plainclothes officer at the time, was right behind him when he felt a sharp crack to the back of his head.

He fell to the ground and more blows followed—to his forehead, his ribs, his face. Other police officers, who had been farther back during the car chase, had mistaken Cox, a Black officer dressed in street clothes, for a suspect. Officers surrounded him, kicking and punching, until one of them noticed his police badge under his jacket.

“Oh my God,” one of the officers breathed. Cox passed out. There was a long stretch of silence before anyone called for an ambulance.

While Cox was shocked by the viciousness of the beating, he could almost understand how officers might have mistaken his identity. Almost. It was dark, his badge was under his parka, the chase had been intense, and sometimes in police work, a split-second decision means the difference between life and death. What he couldn’t understand—and still can’t—is the lie that followed.

His fellow police officers closed ranks. They told his wife that Cox had slipped on a patch of ice. They wrote police reports that obscured what actually happened. Cox spent six months recovering from the most acute of his injuries. He spent four years waiting, and eventually demanding, in the form of a civil lawsuit, for some acknowledgment of what happened to him. He expected, if not justice, then at least an apology.

Throughout all this, Cox was threatened, harassed, made a pariah in the department. But he never left. He stayed on the force, his presence a testament to a dogged determination to keep doing a job he loves.

“I was thinking, ‘Why would I want to leave this job because some knuckleheads that maybe shouldn’t have been on the job in the first place are trying to force me out?’” says Cox. “So, I chose to stay.”

As he lay in bed at home recuperating from the beating, Cox waited for an apology. He expected to hear from the officers who were responsible—or, at the very least, some acknowledgment from department brass. His belief in justice gave him confidence that the officers who mistook him, who hit him and left him out to dry, would do the right thing. Cox believed that right would win out over wrong.

But the silence stretched on. Instead of offering an apology, officers wrote false or misleading reports that downplayed Cox’s injuries to mere clumsiness, Lehr writes in his book The Fence: A Police Cover-Up Along Boston’s Racial Divide, which he based on testimony, court documents, and interviews with those involved. Boston police investigators were similarly stonewalled: almost every officer they interviewed from that night said they hadn’t seen anything and didn’t know anything.

“I just don’t understand how I can be dehumanized in that way,” Cox says in a recent interview. “And to have no one understand, and no one stand up for me? I was struggling.”

His family urged him to quit the force and go public. Local activists and advocates called his house to let him know they were ready when he was. At the same time, the message he was getting from his department was: Let it go. Don’t make this a messy public affair.

“There was certainly a period of time when I thought about leaving,” Cox says. “A lot of people thought that I should leave. But I’ll be honest with you: when I came on the job, I wanted to help people. I loved the job, and I worked really hard. I was an active police officer, actively involved in busting up gangs, arresting real criminals, murderers—things of that nature. I really felt that I was doing God’s work, so to speak.”

So, Cox found a third way. He sued the city and several officers for violating his civil rights. He was ostracized from the department when he did, but he remained on the force.

And in August 2022, nearly 30 years later, Michael Cox, 57, was appointed commissioner of the Boston Police Department.