NEW YORK » The bodies were discovered throughout the first-floor railroad flat in Brooklyn, a bizarre still-life of death. Many of the victims remained seated in chairs or couches; one woman’s hands still held a spoon and a small can of pudding.

It came to be known as the Palm Sunday Massacre, the largest mass shooting in the New York area in decades. Ten people were killed that day 30 years ago, including eight children. Only one survivor was found: a crying toddler covered in blood, crawling at the feet of the dead.

The tiny girl was handed to one of the first police officers to arrive. A front-page photograph in The New York Post, under the headline "The Only Survivor," shows the officer clutching Christina Rivera, 13 months old, a pacifier in the child’s mouth.

The officer was assigned to the toddler through the night, taking her to the hospital and then watching over her at a police station in East New York. Since that day, the officer has never really let go.

The officer became the girl’s benefactor, then a surrogate parent. At age 14, Christina moved in with the officer and her new husband. And then last year, the officer adopted Christina, now 31.

It is a remarkable story, never told publicly before and little known even at Police Headquarters, where the officer, Joanne Jaffe, rose to become the Police Department’s highest-ranking female chief. But as the 30th anniversary of the massacre approached, Jaffe and Rivera came forward, telling of an unlikely relationship that emerged from one of the city’s most gruesome crimes.

"I can’t imagine my life without her," Rivera said last week. "She taught me what it was like to hope and to truly trust; if ever in life I didn’t think things would work out, I could trust her, and I would just put all my trust in her and she would get me through to the other side."

By April 15, 1984, Jaffe had already spent nearly four years in the 75th Precinct, one of Brooklyn’s most violent. But nothing approached the horror that awaited inside 1080 Liberty Ave. Among the dead were Christina’s mother, Carmen Perez, 20, and two half-brothers, Alberto, 5, and Noel, 3; and several cousins.

With guns drawn, Jaffe and her partner went from room to room, looking in vain for the killer, who turned out to be Christopher Thomas, a cocaine addict arrested two months later.

Christina had been brought outside by a neighbor, and she would soon find her way into Jaffe’s arms.

"I was assigned to her and fell in love with her," Jaffe recalled.

That night, Jaffe asked to take the baby home, but child welfare services instead arranged for Christina to stay with a foster family in Coney Island. Two detectives rode in the front, with Christina and Jaffe in the back.

Christina would be reunited with her father, a building superintendent in Manhattan, but was sent to live with her grandmother Felicia Rivera. Christina grew up on a bad block in Washington Heights in Upper Manhattan, her grandmother devoted but overprotective. She was not told what had happened that Palm Sunday. Her grandmother once mentioned that Christina’s mother had asthma; from that, the girl concluded, her mother must have died of an asthma attack.

The truth came out when she was about 10. One day, Christina came home from school agitated: A girl told her that her mother had been murdered.

"Are you ready for this?" her grandmother asked.

A gray suitcase emerged, stuffed with laminated newspaper clippings, telling of the murder of not only her mother but of two siblings she never even knew she had. One of the articles had a diagram of where the victims were found, some in front of the television, others napping on a bed. Christina fixated on the woman with the spoon, she said. "I remember focusing on that detail," she recalled. "Who were they feeding?"

By then, Jaffe said, she was already a presence in Christina’s life. She would drop in to play with Christina, leaving behind a gift for the child and some spending money for the grandmother.

In vague terms, Christina was told by her grandmother that Jaffe "had been there from the beginning." Slowly, Christina began to realize what her grandmother meant.

"I really began to grasp that she was a first responder there," Rivera said. "I can remember starting to ask her about it: hesitantly first, because I didn’t know what her reaction was going to be. But she was always very good about it."

Christina, who thought of Jaffe as "the funny police lady who would come by," began to think of her as her mother.

The transformation began with a coincidence. Jaffe, then an up-and-coming commander with a voice demanding attention, had been reassigned from a quiet precinct in Tribeca to lead a crime-ridden precinct in Washington Heights. She immediately thought of how near she would be to Christina, who lived only two blocks from the station house.

Jaffe soon visited the apartment on an early afternoon. Christina was home because her grandmother was feeling too ill to walk her to school. When she saw Jaffe in full uniform, Christina recalled recently, she mistakenly thought she might be in trouble for truancy.

The visits would become more frequent, and Christina started dropping by the station house after school, playing games on a sergeant’s computer. On weekends, Jaffe began taking Christina on trips with her fianci, Doug Lennihan, also a police officer, to a relative’s place in Connecticut. Christina went fishing and stomped through the woods – new activities for her.

"It was unbelievable to watch her thrive, this little scared child," Jaffe recalled.

As Christina entered her teenage years, the challenges of schoolwork and adolescence became too much for her grandmother . One day, Christina’s father and grandmother appeared at the precinct house with a request.

"They said, she gets along with me, she loves me, and they just said, ‘Could I raise her? Could I take her?’" Jaffe recalled.

"I always wanted to have more of a role – I never in my life thought it would turn into where she’d come to live with us."

She wanted to say yes, but she was about to be married.

Jaffe suggested to her fianci that they wait a year before taking Christina in.

"I thought we should settle down and get married first," she said.

Lennihan, who had three older children from an earlier marriage, reacted quickly.

"I said, ‘Sure, let’s take her, let’s bring her in,’" recalled Lennihan, who has since retired from the department as a lieutenant. "This was after we had taken Christina away for all these weekends and we were involved with her. I really liked her. I loved this little kid."

Once they were together in the couple’s new home in Queens, Jaffe came to see Christina’s turmoil firsthand.

At times, Christina would ask questions about the murder of her mother. She wanted to know where precisely in the home she had been found. During one spell, she sat with a headset on, listening over and over to a recording of a 1984 news radio account about the murders, trying to discern some new hint or clue about what had happened.

"There is this huge hole – that’s what I call it – in her soul. She had lost her mother," Jaffe recalled. "We could only fill the hole, but it could never be removed."

The new parents also realized that they needed to do more than simply raise a teenager; they needed to instill a sense of self-reliance and confidence in Christina.

It has been a gradual process. In Washington Heights, Christina had slept in the same bed as her grandmother; now, for the first time, she slept alone.

With considerable prodding, Christina began venturing out of the apartment herself. A big step was in overcoming her anxiety to go to the corner store to buy milk by herself; eventually she would work up the courage to travel alone from Queens to Manhattan to visit Jaffe, who by then had moved to the 19th Precinct on the East Side.

"Getting her to take the bus on Queens Boulevard to the city was huge," Jaffe recalled. "Chris thought she would get lost, or have a panic attack."

Christina had a tendency to cling to Jaffe, emotionally and physically.

"There wouldn’t be more than a foot of space between us, and I’d bump into you," she told Jaffe recently. She said she kept close because she feared her new mother would disappear.

That fear of abandonment led Christina to resent Lennihan, whom she viewed back then as a rival for Jaffe’s attention. Her entries in a journal grew darker. Concerned over this, as well as the long hours that Christina spent by herself at home while they were on duty, the couple approached Christina’s father and made arrangements for her to live with him in Manhattan after about a year.

Only once did she ask her father what her mother had been like.

"He got very quiet for the rest of the day," Christina recalled years later. She has never asked him again, she said.

Christina graduated from Baruch College Campus High School, and, with help from Jaffe and Lennihan, went off to a New York State college. She struggled there and left college after five years.

In her early 20s, Christina decided to learn more about her mother’s life. She and Jaffe made their first visit to the graves of her mother and two half-brothers.

"I remember being surprised at how young she was," she said, recalling seeing her mother’s birth date on the tombstone. "I wanted to know what she meant to people, what she was like."

Jaffe recalled that she had told Christina that her mother would be "unbelievably proud" of her daughter and "what a caring, thoughtful person you were." But Christina found no deeper meaning or connection in the visit; she said she "wasn’t at a place yet where I could let it reach me."

She would come to better understand the significance of her loss a few years later while working at an office day care center. One day, a little girl began to cry. Rivera picked her up and tried to comfort her, but the child was inconsolable. Eventually, Rivera called the child’s mother, who was nearby. When the mother arrived, the child almost leapt from Rivera’s arms to her mother’s. The crisis was resolved.

But Rivera kept thinking about it. Later, in a therapy session, she realized that she was really thinking of herself: She had been the same age when she was held by a young police officer that night on Palm Sunday. She, too, must have missed her mother and waited for her to return, not realizing "she was never going to come back," she recalled.

"Just like that the floodgates were opened," Rivera said. "It was almost like I had delayed grieving for 22 years and all of a sudden it just hit me."

Over the past few years, Rivera has grown in confidence. She has a job with the state and has become an auxiliary police officer. But the events of April 15, 1984, are never safely in the past.

In 2009, she and Jaffe began attending parole hearings for Thomas, who was found guilty of 10 counts of manslaughter but was acquitted of murder because the jury believed he had acted under extreme emotional distress and the influence of years of drug abuse. There was some evidence that Thomas believed his wife was sleeping with the man who lived at the home on Liberty Avenue. Neither was present at the time of the rampage, the authorities said, and Thomas killed the women and children he found.

Around this time, Christina’s grandmother died; the death had a profound effect on her, and led Jaffe to follow through on a promise that she made when Christina first came to live with her: She would adopt Christina.

For a number of reasons, the adoption had not happened, a fact that was often brought up by Rivera during arguments over the years.

"I felt very orphaned, if that makes sense, even though my mom was still my mom and still there for me," Rivera said. "It was almost like I wanted to be claimed, like, ‘I’m her daughter, I belong to her.’"

A little more than a year ago, Jaffe fulfilled her pledge.

"I’d seen her ups and downs in life and I said I owe it to this kid," she recalled. "I thought that maybe I was part of the hurt – I’d promised her as a kid and I never followed through. I thought this is what she needs if that hole in herself is ever going to be filled."

She told her husband about her intention; he reminded her of another reason to go forward.

"He would say, ‘It’s for you, too. You need it, too,’" the chief recalled.

She sometimes overlooked how badly she, too, wanted to make it official.

"I never saw that part of it."

Joseph Goldstein, New York Times