Pamela Cisneros was in the grip of a mental health crisis seven years ago when, her father said, she tried to jump in front of a subway train in Queens.

She had lived for decades with serious mental health problems, her father, Mario Cisneros, said in an interview on Tuesday. But the episode in the subway in 2019 had prompted her family to intervene.

Mr. Cisneros began taking her to monthly hospital appointments, where she would receive injections that helped keep her stable. He believed his daughter had finally turned a corner.

Then, in April, he said, she refused a ride to her regular mental health appointment at Jamaica Hospital Medical Center in Queens, saying she could go to treatment alone.

“No, Dad, don’t worry,” he recalled her saying. “I’m good. Don’t worry about me.”

On Monday, Mr. Cisneros learned that his daughter had carried two kitchen knives with her through a bustling Times Square in Manhattan and, seemingly at random, had attacked two people, killing one of them. Minutes later, she was fatally shot by the police after refusing to put down the weapons. She was 49.

“She was a noble and polite girl, a Christian. But all of a sudden she acted like an animal,” Mr. Cisneros, 78, said in Spanish.

He said he did not know what type of medication she had been receiving or what condition she was being treated for, and it was unclear whether she had taken medication recently or received mental health treatment. But in recent months, Mr. Cisneros recalled, his daughter had said she did not want to rely on medication to feel normal.

“She didn’t want to continue them,” he said. “She was fighting to not be on the medicine, to not have to depend on it.”

“We tried to help her in every way possible,” he added.

As the authorities on Tuesday examined what might have led to the attacks, court filings and police records offered glimpses of the turbulence, financial woes and mental health struggles that had at times punctuated Ms. Cisneros’s life.

She had lived in Queens and studied psychology in college. She got married in September 1999, and had three children with her husband, Jose Lopez, according to Mr. Cisneros and court records.

Still, Ms. Cisneros struggled to hold a job, according to a bankruptcy petition filed in the Eastern District of New York in 2005. She reported being unemployed, while her husband worked as an office clerk at Citibank in New York. They reported having about $14,000 in assets.

At some point, it appears they moved to Florida. By 2018, the couple had separated, and Ms. Cisneros had moved back to Queens, according to records filed in family court in Hillsborough County, Fla.

It was during this time that Ms. Cisneros appeared to begin her spiral. On Dec. 20, 2018, police officers in Manhattan found her screaming and belligerent on Lexington Avenue near 49th Street, and determined that she was intoxicated, according to an internal police report obtained by The New York Times.

Less than four months later, on March 6, 2019, she tried to jump in front of the train in Queens. Mr. Lopez filed for divorce the following year in Florida, and a custody battle for their youngest daughter ensued, Florida court records show. Mr. Lopez could not be reached for comment.

Ms. Cisneros still had not found steady employment. In February 2022, she reported that she had left a position at Aflac, the insurance company, and could not find a job in her field, the Florida court records showed.

In the records were screenshots of months worth of text messages Ms. Cisneros had sent to two of her daughters. She had wished them a Happy Thanksgiving, a Merry Christmas and a Happy New Year.

“Remember that mommy will always be here for you and your sisters,” Ms. Cisneros wrote in one. “I love and miss you.”

The text messages went unanswered.

For the past five years, she had lived alone in an apartment building on a quiet and tree-lined block in Woodside, Queens.

“Literally she said hello and goodbye, paid the rent on time. Never had a problem with her,” said Chris Dowling, 46, the manager of the building. “I never heard a peep out of her.”

On Tuesday, shaking his head as he stood in the rain outside his own apartment building in Queens, Mr. Cisneros wondered what had gone so wrong. He said his daughter had been troubled, but never violent. She had been at his home for dinner just 10 days before and nothing seemed amiss, he said.

“What she did just doesn’t make sense,” Mr. Cisneros said. “It just doesn’t fit.”

“I am so sorry, as her father,” he added. “Nobody should take a life. Not God, not a human being. Nobody.”

Kitty Bennett contributed research.