Nyla Bond, 20, met Anmerie Morales, 15, about a year ago. Despite their age difference, they became friends and often spent time together at the Bronx apartment where Ms. Bond lived with her mother.
But there was friction between them, according to Ms. Bond’s mother, who said that Ms. Morales had attacked her daughter with a knife in October. Rather than spurn the teenager, though, Ms. Bond forgave her. Ms. Bond’s mother attributed the response to a mental illness her daughter had that gave her a childlike naivete.
Three weeks later, Ms. Bond was dead after being beaten with a cane and stabbed, and Ms. Morales and another 15-year-old had been charged with murder.
They joined a growing list of young New Yorkers accused of violent crimes: three teenagers charged in the fatal stabbing of a Barnard College student last year; a 15-year-old boy charged with five counts of attempted murder in a shooting at a West Indian celebration in September; two boys, 16 and 17, charged with murder in the April killing of a Brooklyn man in his home; a 15-year-old boy charged with fatally shooting two teenagers playing basketball.
Ms. Morales and her accused accomplice, Nore Hatchett, are being held in a juvenile detention center but have been charged as adults. A criminal complaint that contains the charges against them says a third person took part in the killing and is still being sought.
The complaint does not cite a motive, but there are indications that sexually explicit photos of Ms. Morales may have played a role.
Mr. Hatchett told investigators that he and Ms. Morales confronted Ms. Bond because they believed she had shared such photos online, the police said. But that is just one possible factor the authorities have been exploring, according to a law enforcement official who spoke on the condition of anonymity because the investigation is continuing.
Javier Solano, a lawyer for Ms. Morales, denied that she had killed Ms. Bond. He confirmed, however, that explicit photos of his client had been shared widely on social media, although not by Ms. Bond.
Instead, he said, it was one of the two other people accused of playing roles in the killing — Mr. Hatchett and the person still being sought — who had shared the photos. Mr. Solano did not indicate what role the photos may have played in the killing of Ms. Bond.
A lawyer for Mr. Hatchett, Archana Prakash, declined to comment on the specifics of the charges, but in a statement she cautioned against “rushing to judge this child.”
“No one is served by a rush to judgment while we are all still in the process of investigating and understanding the facts surrounding this tragic incident,” Ms. Prakash said.
Ms. Bond was born and raised in the Bronx, her mother, Shadonna Watson, said. As a child, she enjoyed writing and playing basketball. She attended KIPP Infinity Middle School in Manhattan. School staff members who organized an online fund-raiser for her family described her as having “an unflappable sense of humor, a hugely forgiving heart and a quiet warmth.”
About four years ago, her “mental state started to decline,” Ms. Watson said. She was told she had schizoaffective disorder. After that, Ms. Watson said, her daughter’s friendships became strained.
She was never dangerous, Ms. Watson said, but she would sometimes behave erratically, kicking things or rushing out of the apartment. She did not graduate from high school.
“It kind of regressed who she was,” Ms. Watson said, referring to her daughter’s disorder. “She was much more mature as an adolescent.”
Ms. Watson said it was her son who had first been friendly with Ms. Morales, and that Ms. Bond had met her through him. When Ms. Morales visited the family’s apartment, she was friendly but distant, Ms. Watson said.
Mr. Solano, Ms. Morales’s lawyer, said her client had also been born and raised in the Bronx and that she and Ms. Bond would play basketball together. Ms. Morales’s upbringing had been difficult, he said, and she had gotten into fights and had experienced problems with her family “like any other 15-year-old.”
On Oct. 13, Ms. Bond reported that Ms. Morales had attacked and stabbed her, Ms. Watson said. Asked to confirm the episode, the police said only that a 20-year-old woman had complained to them of being slashed in the face and stabbed in the back after a verbal dispute.
Mr. Solano said he was unaware of Ms. Morales’s possible role in that encounter, but he questioned why she was not arrested if the police believed she was involved.
On Nov. 2, the police said, officers responded to a 911 call about an assault at a different Bronx apartment building. Ms. Bond’s father lived at the address, Ms. Watson said. She said she believes her daughter’s attackers lured her there.
Officers found Ms. Bond with a stab wound in her chest, the police said. Emergency medical workers took her to Bronx Lebanon Hospital Center, where she was pronounced dead.
Ms. Bond gave birth to a son last year. The boy, Chance, will turn 1 on Thanksgiving.
“She was a beautiful person,” Ms. Watson said. “What happened to her, she definitely didn’t deserve.”
Ashley Southall contributed reporting. Sheelagh McNeill and Susan C. Beachy contributed research.