The bullet, fired by a police officer who was sprinting into the 3 a.m. darkness, struck Khalif Cooper with improbable precision.

The projectile penetrated the young man’s lower back before ripping through organs and coming to rest near a vertebrae that controls lower-body movement. By morning, Mr. Cooper had lost a kidney, half his colon and his ability to ever walk again.

“My whole life just changed,” Mr. Cooper, who is 29 and Black, said in his first interview since the shooting.

It happened on a warm Saturday last June in Paterson, N.J., and Mr. Cooper, the father of two young daughters, said he was running away from the sound of gunfire.

A police officer, Jerry Moravek, came racing down the sidewalk toward the same noise. Their paths crossed, footage from a police body camera shows, and Officer Moravek pivoted to begin chasing Mr. Cooper, convinced that he was holding a gun.

Months later, Officer Moravek would be charged with aggravated assault for his decision to fire his weapon, without warning, toward a man who was running away. In March, the shooting would become one of the many data points used to justify the state attorney general’s decision to take the rare step of seizing control of the troubled Paterson Police Department.

But that is largely beside the point to Mr. Cooper. He worries most these days about his inability to help when his daughters cry and the mild humiliations that define his day-to-day existence. He cannot hoist himself out of his wheelchair into bed without help, and his girlfriend, who gave birth to their daughter a week after the shooting, now must change his diaper, too.

“There have been times when I just couldn’t take it, and I was, like, ‘I just want to die,’” he said.

Mr. Cooper had had past run-ins with the police, and he had been released from prison less than two years earlier after serving time for weapons and drug convictions. But he has not been accused of doing anything wrong the night he was shot. And a gun found about a block from where he fell held none of his DNA or fingerprints, court records show.

“Why did you run from me?” the officer asked Mr. Cooper after pulling his wrists into handcuffs, according to video released by prosecutors. “I was scared,” he answered.

Narcia Cooper, Khalif’s mother, spent nearly every day at her son’s bedside during the three months he was hospitalized. She still cannot make sense of why he was shot. “If someone is running away from you, why shoot them?” she asked.

Many police shooting victims’ names become rallying cries for reform upon death. As someone who survived, Mr. Cooper understands the power he now holds as a bleak, living reminder of America’s policing crisis.

“What I experienced — I don’t want nobody to ever go through this,” he said.

This week, Mr. Cooper filed a $50 million federal lawsuit against Officer Moravek, the City of Paterson and its former police chief and police director. He has dual goals: locking in enough money to pay for a lifetime of medical care and driving home a point.

“We pray that the good cops keep being good cops,” said Kenyatta Stewart, who grew up with Mr. Cooper in Paterson and is one of three lawyers representing him, “and the bad cops understand what can happen when you make these decisions.”

Officer Moravek remains on paid leave. Paterson’s mayor, André Sayegh, said the city does not comment on pending litigation. Officer Moravek’s lawyer, Patrick Caserta, could not be reached for comment, but he has said that his client made a split-second decision based on a belief that his life and the lives of people nearby were at imminent risk.

Isa M. Abbassi, a former New York Police Department chief who was instrumental in crafting the city’s strategy after the 2014 police killing of Eric Garner on Staten Island, has been in charge of the Paterson department since early May.

“We have already begun the process of providing supplemental training for our members in the areas of constitutional policing and use of force,” Mr. Abbassi said on his first day on the job.

“The next generation of public safety starts today,” he added, “and it starts in Paterson, New Jersey.”

With 157,000 residents, Paterson, which is about 20 miles northwest of New York City, is the state’s third-largest city.

It has its landmarks. Hinchliffe Stadium, one of the last Negro Leagues ballparks still standing, reopened in May behind the Great Falls, a hydropower behemoth that fueled the country’s Industrial Revolution. Over the past two decades, refugees from Afghanistan and Syria and elsewhere, eager to build new lives, have flooded the welcoming city.

But unlike Newark and Jersey City, the state’s two larger cities, which are closer to the shimmer of New York City and benefit more from its reflected glow, Paterson has struggled for economic traction.

Its schools, under state control for 30 years until 2021, were shut during the pandemic for longer than all but one other district in New Jersey. Last spring, 46 percent of the city’s third-graders scored at the lowest level on standardized reading tests, more than twice the statewide failure rate.

And of the 46 fatal encounters with New Jersey law enforcement officials since 2019, eight were in Paterson — more than any other community in the state, according to an analysis by NJ Spotlight News.

Every year in the United States, more than 80,000 people suffer nonfatal injuries during contact with law enforcement officials, according to a University of Illinois Chicago study of data collected by the Centers for Disease Control and Prevention. In 2018, the most recent year with all relevant figures available, 54 percent of those injured were Black, even though African Americans make up only about 14 percent of the country’s population.

Before the shooting, Mr. Cooper said he never felt particularly distrustful of the police. “I look at cops like they’re people, they do what they got to do,” said Mr. Cooper, whose uncle and cousin are both police officers in Paterson. “That’s their job.”

Dennis Hickerson-Breedon, one of Mr. Cooper’s lawyers, said it would be impossible to know what Officer Moravek was thinking when he pulled the trigger. Still, he said he believed that Mr. Cooper’s well-being “was much more expendable than a person who may live in a more suburban neighborhood.”

The lawsuit, filed in U.S. District Court in New Jersey, argues that Officer Moravek fired his weapon on June 11, 2022, “without need, justification or cause,” in violation of Mr. Cooper’s civil rights.

In spring of 2022, Mr. Cooper had moved with his girlfriend, Kaelah Pace, to Sugar Notch, Pa., about two hours west of Paterson by car, and had been preparing to start work at a pet food supply company, the couple said. His lawyers said he was in Paterson the weekend of the shooting to see his older daughter, who is 6.

Police body camera video from that night shows about a dozen people milling around outdoors. Officer Moravek pulls up in a police car at about 3:15 a.m. and explains to them that several neighbors had called to complain. Then, over the radio, another officer reports having a suspect with a gun in custody. Seconds later, three shots ring out, and Officer Moravek begins running toward the noise, encountering Mr. Cooper along the way.

“Drop the gun,” he shouts several times, but never orders Mr. Cooper to stop or warns that he is about to shoot — omissions the attorney general said were violations of the state’s use-of-force policy when he charged Officer Moravek with assault and official misconduct.

The bullet has never been removed from Mr. Cooper’s back. For now, he said, it is safer to leave it untouched.

Ms. Pace, a certified nursing assistant who also has a 5- and a 7-year-old, is his main caregiver, but physical therapists and nurses visit regularly. Wound care, managing a diet that is easy on his remaining kidney and the strain involved in lifting Mr. Cooper in and out of the wheelchair are constant struggles.

“It’s just a lot,” Ms. Pace, 23, said before starting to cry, awakening their 1-year-old daughter, who began to fuss.

Mr. Cooper reached out and placed her on his lap in the wheelchair, and the baby smiled.

“She thinks it’s a ride,” he said.

Mr. Cooper said he missed the small things most: walking to the park; being able to swim with his daughters; the dream of eventually having another child.

“I wish I could go back. I wish I could go back in time,” he said.

“But I’ve got to keep going for my kids — you know? — for my daughters.

“They give me life.”