Two women, grieving from opposite sides of a murder, are searching to understand and reconcile why one woman's husband is dead and the other's son is accused.

In Rock Hill, Wanda Sterling doesn't dispute what police have charged: that her son Chauncey went looking to rob someone mid-morning on Good Friday, spotted Robert Barber walking alone through a residential neighborhood in south Charlotte and shot him during a hold-up.

"I apologize to the other family," Wanda Sterling said. "... It's so wrong. If he's done that, he needs to be punished."

In Charlotte, Barber's wife, Debbie, said she is still in shock, still expecting her husband to walk in the door. "Everything has a memory," she said. "I am blessed to have had him in my life and it's going to be really hard not to have him."

Holding her youngest son's hand, and flanked by more than 70 friends, co-workers, neighbors and strangers, Debbie Barber on Saturday retraced the steps her husband took on that fateful morning. They walked from the Caribou Coffee on Fairview Road, along tree-shaded Simsbury Road, over a tiny creek, and then turned left onto Mullens Ford Road and up to the spot in the 4500 block where he was slain.

They stood, heads bowed, for a moment of silence and honored a life well lived.

In most murders, the victim and killer know each other, according to the federal Bureau of Justice Statistics. In only 14 percent of all cases, they are strangers.

So how, as police charge, did 64-year-old Robert Barber and 18-year-old Chauncey Sterling end up on the same street corner at the same time?

"That element of randomness is not incomparable to a tornado," said Joseph Kuhns, associate professor in UNC Charlotte's criminal justice and criminology department. "It's not something likely to happen to most people."

The paths that apparently led them together on April 22 are as different as the men themselves.

Hardworking executive

Though originally from New Mexico, Barber moved to Greensboro in 1985 after reconnecting with his high school sweetheart, Phyllis Allran. They married and moved to Charlotte, where she worked as assistant to Tony Zeiss, president of Central Piedmont Community College, and he worked for the Nalle Clinic and Mercy Hospital before joining Carolinas HealthCare System.

In 1996, after 10 years of marriage, Phyllis died suddenly due to complications from a severe asthma attack. The Phyllis Allran Barber library at CPCC's Levine Campus is named in her honor.

In 1997, Barber met and fell in love with Debbie, who works as a nurse in outpatient recovery at Presbyterian Hospital. They married a year later, and she said Bob embraced her two teenage sons as his own. He joked that they had "a mixed marriage" because of their jobs with different hospitals.

Barber, who went by Bob, was a serious, hardworking executive. But Michael Tarwater, CEO of Carolinas HealthCare, said that during meetings, when it was least expected, the corners of Barber's mouth would turn up into a smile and, with his understated wit, Barber would say something to make everyone laugh and lighten the mood.

Tarwater compared Barber to a designated hitter in a baseball game: He was the go-to guy for straightening out problems in hospitals that Carolinas HealthCare acquired.

Off the job, he had a wide range of interests. He raced Corvettes when he lived in New Mexico and liked NASCAR, and he also enjoyed crossword puzzles and genealogy. He trained 33 years in the military reserves, first in the National Guard, then with the Air Force Reserve. He helped coordinate relief efforts during flooding in Eastern North Carolina after Hurricane Floyd, and he and Debbie volunteered in New Orleans after Katrina.

"He always tried to do the right thing," Debbie Barber said.

In a big zippered binder he carried with him was a quote by William Penn that spoke to the kind of life he aspired to: "I expect to pass through life but once. If, therefore, there be any kindness I can show, or any good thing I can do to any fellow being, let me do it now and not defer or neglect it, as I shall not pass this way again."

Mentor to young people

Despite the hours Barber devoted to his job, he also found time to teach health administration at several colleges. To many students, he was a mentor. To colleagues, he was "Dr. Bob."

"He took on too many things," stepson Eric Hartley said, "but everything he did, he did completely. It was really impressive." Hartley said that after Barber was killed, he read his stepfather's daily journal and discovered that some nights he stayed up late answering students' emails and got only about 2 1/2 hours of sleep.

"The irony there," Tarwater said, "is the young guy they have locked up for shooting him is that age. There are probably hundreds of kids in their late teens and twenties, and people just starting their careers, who were helped through Bob's teaching them or advising them or mentoring them. He had a soft place in his heart for young people."

Barber usually carried a grappler to pick up trash along the side of the road. He wasn't carrying it with him on the morning he was killed, his stepson said, because it was raining and he hadn't expected to walk home. He drove to the coffee shop with his wife. She said that when she left to go to work, he decided to wait for the rain to slacken and walk the nearly three miles home. He was borderline diabetic and trying to lose weight, she said, so he wanted the exercise.

From the coffee shop, he would have passed several apartment buildings before heading into the section of Mullens Ford Road with houses.

It was there that police say he encountered Chauncey Sterling.

Troubled teenager

Wanda Sterling did not raise her youngest child to be a murderer. She said she is a single mother, works in a school cafeteria and money is tight. She has faced eviction multiple times. But she said she would have given her son anything he wanted.

"That's my baby," she said, her voice choking, in an interview at her apartment in Rock Hill a few days ago. She apologized for her own grief in the face of what Barber's family is going through. "I know the other family is hurting, too," she said. "That wasn't my real boy. Something triggered him off."

In her living room are photographs of Chauncey Sterling as a baby and as an older boy. "He was the sweetest person," she said. "He would hug you."

But as a teenager, he was floundering. She said in the last few years, he got mixed up with someone she described as "trouble."

His Facebook page was filled with the invectives of an angry youth: "U knw lately i been n dis zone like i dnt give a f--- , " he said in his last post on April 17, five days before the murder.

James Blake, principal at Northwestern High, said Sterling struggled academically and behaviorally. He had dropped out of school so many times he was classified as a ninth-grader at age 18. Dropping out of school, Blake said, is often a precursor of worse problems to come.

That seemed to be the case with Sterling. He became a father for the second time in March. Then a few weeks later, he was jailed on charges of beating his girlfriend in the head and pushing two of her family members.

In his bedroom closet, next to a Boston Celtics jersey, are two tiny dresses - one pink, the other floral - for his newborn daughter. Squeezed between the foot of his double bed and the wall of the small bedroom are a portable crib and a package of diapers. His mother said he needed a job to support himself and his children, but she said he couldn't find one.

Desperate for money

According to his Facebook page, he desperately wanted money. "Money over everything ---- da world," he wrote.

Police believe he deliberately set out to rob someone to get it.

Sterling was staying with his sister in her apartment on Johnston Road in Charlotte, his mother said. She said he took the sister's gun. How he got to Mullens Ford Road, as police allege, from the apartment six miles away is one of many unanswered questions.

Barber struggled with his killer, police believe, and was shot twice in the chest. Detectives recovered a gun which they believe to be the murder weapon. They have declined to talk further about their investigation.

Wanda Sterling said her son told her what happened: "He told me he killed somebody," she said. "He said he didn't mean to. He said the man grabbed the gun."

Not a typical robbery

Alarmed by the sound of gunfire, a witness looked down from the second floor of a nearby house and saw Barber on his knees and the killer running away. At first it seemed as if it would be a tough case to crack. Murders committed by strangers are among the hardest to solve. "By the time we left the scene, we weren't feeling very good about whether we ultimately had enough information to lead to closure," Police Chief Rodney Monroe said in a news conference.

A tipster eventually fingered Sterling, and family members led detectives to him on Easter Sunday.

It wasn't a typical street robbery, Monroe said. It happened mid-morning on a day when people were at home for a holiday weekend. It was rainy. "But again," Monroe said, "most of these things never ultimately make any real sense to us."

An accomplished man - husband, stepfather, community leader - is dead. A teenager is in prison.

Bob Barber's family and friends want people to remember him not for how he died but for how he lived.

"The circumstances of his death have us stunned and confused, angry and grieving," the Rev. Katherine Cooke of First Presbyterian Church said at his funeral, but she added: ".... The tragedy of Bob's death does not overcome the beauty of his life."

Researcher Maria David and staff writer Cleve R. Wootson Jr. contributed.