The ongoing investigation into the mysterious death of Ellen Greenberg, a Pennsylvania first-grade teacher found with over 20 stab wounds in her Manayunk apartment, has taken a new turn. Sources reveal that the U.S. Attorney’s Office for the Eastern District of Pennsylvania has requested to examine details surrounding the case.

According to NBC 10 Philadelphia, last month the federal authorities sought access to documents from the Philadelphia Police Department and other relevant agencies to shed light on this perplexing case.

Currently, it remains unclear when the federal team began their involvement or when they might disclose further information regarding the investigation.

Though the sources providing this information preferred to stay anonymous, a spokesperson from the U.S. Attorney’s Office mentioned that the office would “neither confirm nor deny the existence of an investigation,” as reported by The Philadelphia Inquirer.

As reported earlier by CrimeOnline, Ellen Greenberg was discovered dead in her apartment back in 2011. Her fiancé, Sam Goldberg, recounted that he had left her chopping fruit in the kitchen while he went to the gym. Upon his return, he found the apartment’s front door locked from the inside with a swing lock.

He returned home to find the front door locked, with the swing lock attached to the inside side of the door.

Goldberg said he called and texted Ellen numerous times, but when he couldn’t get an answer and couldn’t get help from the apartment management, he broke the lock and walked inside.

Ellen was found slumped over in the kitchen, with “some of her upper body/shoulders resting against the lower half of the white kitchen cabinets,” according to court documents.

Goldberg has not been named a suspect in the case.

CrimeOnline’s Nancy Grace, who co-authored the book,”What Happened to Ellen?: An American Miscarriage of Justice,” questioned the cause of death during CrimeCon Denver, referencing Ellen’s behavior shortly before the stabbings.

“She filled up her car with gas…forward-thinking. When you’re suicidal, you’re not thinking about filling up your car,” Grace said.

Nancy Grace Highlights Ellen Greenberg’s Controversial Death at CrimeCon Denver

Meanwhile, the attorney for the Greenberg family, Joseph Podraza Jr., said that Ellen’s parents, Dr. Josh and Sandee Greenberg, are “ecstatic” about the information.

“If that is in fact correct and accurate, that the federal government is going to investigate … this is exactly what we’ve wanted all along,” Podraza Jr. said.

“It’s unfortunate it’s taken more than seven years to get to this point but we are really grateful and thankful to the U.S. attorneys and, of course, are available to assist in any way we can in helping their investigation.”

Check back for updates.

[Feature Photo: Ellen Greenberg/Family Handout]