Ellen Greenberg’s mysterious 2011 death is back under the microscope—and this time, it’s the feds turning up the heat.

Almost 15 years after the 27-year-old Philadelphia teacher was found lifeless and covered in twenty gruesome stab wounds in her apartment, federal prosecutors are demanding answers that have eluded her shattered family for years.

The U.S. Attorney’s Office for the Eastern District of Pennsylvania has reportedly fired off subpoenas to the Philadelphia police and other local agencies, digging into what some call one of the city’s most confounding death investigations, sources spilled to The Philadelphia Inquirer. Greenberg’s harrowing end stunned experts: she was discovered by her fiancé Sam Goldberg on January 26, 2011, slumped by the kitchen cupboards, a 10-inch blade still stuck in her chest, and ten of the stab wounds puncturing the back of her neck.

From the get-go, doubts surrounded what happened that dark winter day. Detectives at first called it a homicide, rocking Ellen’s loved ones—but a mere two weeks later, officials abruptly switched gears and called it a suicide, despite the shocking circumstances. The controversial ruling fueled a relentless legal campaign by her parents, Josh and Sandra Greenberg, who have spent over a decade insisting their daughter was killed and that authorities swept a bungled investigation under the rug.

Now, the arrival of federal investigators signals a dramatic twist. Law enforcement insiders say the feds aren’t re-litigating how Ellen died—instead, they’re scrutinizing how the entire case was managed over the past fifteen years. Was there mishandling, or even criminal corruption in the agencies’ response? The long list of players now under the spotlight includes the Philadelphia Police Department, the city’s Medical Examiner, the District Attorney, the Law Department, and Pennsylvania’s own Attorney General.

Just how deep the federal probe goes is still anybody’s guess. When asked for details, a spokesperson for the U.S. Attorney’s Office declined to confirm—or deny—anything to The Inquirer. Meanwhile, Joseph Podraza Jr., attorney for the Greenbergs, told the paper the family is thrilled: “If the federal government is finally investigating, this is what we’ve wanted all along. We’re grateful to the U.S. attorneys and are ready to help however we can.”

For years, the Greenbergs have blasted local officials for rebranding Ellen’s death as a suicide, insisting that the evidence screams murder. “Our daughter did not commit suicide — we know that. She was killed,” Josh Greenberg previously told The Independent, slamming the case as “a disgrace.” As federal agents dig deeper into the botched probe, the family finally sees a glimmer of hope for the answers and justice they’ve desperately sought for over a decade.