She was not his only girlfriend, her sister said, and she suffered.

She would come home to find her on the couch. “Crying, crying, talking on the phone and smoking,” Tiffany Rojas said. “My poor sister.”

By 2017, she had lost a new job at a hair salon and stopped paying her share of the rent at the subsidized apartment she had moved into on Revere Avenue. She still regularly saw her 12-year-old son, who had moved in with her mother, often stopping by to make sure he was bathed and ready for school . But the stretches between her visits grew longer.

Once, she turned up limping and with bruises on her face, said her brother, who asked that he and his mother not be named because they had been threatened in the past by Ms. Rojas’s dealers over her debts. Another time, she called saying she had been kidnapped by dealers and needed hundreds of dollars.

The person who knew more about what happened in Ms. Rojas’s hidden life was a family friend, a taxi driver who had always had a crush on Ms. Rojas, her family said, and gave her rides to appointments with people that he came to realize were her dealers.

The driver, whose name is being withheld because of his role in the investigation, said one dealer had fallen in love with her and offered to give her medication to wean her off street drugs if she moved in with him. But she refused. Another threatened her, and he and the taxi driver almost came to blows.

Ms. Rojas’s bruises came after three women jumped her, a brutal beating that left her walking for a time with a cane, according to the driver.

She bought from many dealers, moving on as she racked up debts or the relationships soured.

Her drug of choice remained painkillers, which go for about $10 per pill on the street in the Bronx, where prescription pills are sold alongside counterfeit ones . “She loved her Percocets,” her mother said in Spanish.