Gemma Hoskins was the retired Maryland schoolteacher who refused to let her own teacher's murder stay cold. She died on September 20, 2026, at 73, a former Maryland Teacher of the Year whose decades of amateur detective work became the backbone of Netflix's true crime documentary series "The Keepers."

Hoskins had been a student of Sister Cathy Cesnik, a young English teacher at Archbishop Keough High School in Baltimore, when Cesnik was killed in 1969 in a case that was never solved. Hoskins carried the unanswered question through twenty-six years of teaching elementary school in Maryland, work that included being named the state's Teacher of the Year in 1992, the same year she was listed among the nation's honorees while teaching at Jarrettsville Elementary School, according to Education Week.

Long after she left the classroom, Hoskins turned back to Cesnik's case. Fellow Keough alumna Abbie Schaub filed Freedom of Information Act requests seeking the FBI's files on Joyce Malecki, another woman whose unsolved death Hoskins investigated alongside Cesnik's, and Hoskins built an online community that drew in more than 500 women who said they, too, had been abused at the school, according to the Global Sisters Report. That grassroots work became the spine of Netflix's 2017 documentary series "The Keepers," which put Hoskins in front of a global audience as an investigator and advocate.

Hoskins made the case her second career. She and podcaster Shane Waters co-hosted "Foul Play: Who Killed Sister Cathy?," and Waters later said they "kept at it for almost eight years because neither of us was willing to let it go quiet," according to the Baltimore Banner. In 2020 she published a memoir, "Keeping On: How I Came to Know Why I Was Born." In 2023 she saw Maryland pass its Child Victims Act, legislation survivor advocates including Hoskins had pushed to get signed into law.

That same year, in a letter to the Banner, Hoskins described the community of survivors she had helped gather: "Thousands of broken angels are rising up together, a real big band of them. Their strength comes from each other and all of us who honor them, respect them, care for them and love them. Institutional power is mighty, but temporary."

Waters announced Hoskins' death on social media the morning after she died. Teresa Lancaster, a fellow Keough survivor and advocate who also appeared in "The Keepers," said Hoskins "genuinely cared about what had happened to her Keough sisters who suffered abuse. She listened, she pursued the truth, and she never stopped seeking answers." Lancaster added that because of Hoskins' "courage and dedication, our truth was finally heard, and people began to listen."

The record she built is concrete: the survivor network, a memoir, a podcast that ran nearly eight years, and a state law that gives other victims more time to come forward. A woman who spent twenty-six years teaching Maryland schoolchildren spent her second act teaching the rest of the country to keep asking who killed Sister Cathy, and why it took so long for anyone to believe the answer.