Jeffrey Epstein associate Ghislaine Maxwell was sentenced to 20 years in prison in 2021, but her attorney is lobbying to secure an early release. 

Who is the man representing Maxwell?

David Oscar Markus has been Maxwell's attorney dating back to her trial in 2021, when she was sentenced to 20 years in prison for her role in a scheme to sexually exploit and abuse young girls with Epstein. Markus has continued to represent Maxwell and was involved in interviews between the Department of Justice and Maxwell, which took place in late-July over a two-day period.

Following the interviews, Maxwell was transferred from a federal prison facility in Tallahassee, Florida, to a Federal Prison camp in Bryan, Texas. Neither the Department of Justice nor Maxwell's attorney explained why she was transferred.

Markus previously told Fox News Digital that "people shouldn't be so quick to judge and throw stones" after Maxwell's move to a minimum security prison camp.

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"I love what I do," Markus said during the interview. "I love representing the underdog. You know, being a criminal defense lawyer isn't for everybody, but it is one of the most rewarding and great jobs there is, and I really enjoy what I do. So, you know, this case, as all my cases, is an honor to be able to help somebody."

While Markus has represented Maxwell going back to 2021, he has also represented other high-profile defendants, including politicians and athletes. 

Markus represented former NBA star Dwight Howard, who was being investigated for alleged child abuse. According to ESPN, Howard was investigated after an incident where he allegedly hit his own child with a belt. 

The former basketball player told authorities he was disciplined in a similar way growing up. While police in Florida and Georgia investigated the incident, no charges were filed.

Former Florida Democrat gubernatorial candidate Andrew Gillum was also among Markus' clients, turning to the lawyer when he was facing corruption charges. Federal prosecutors alleged the former Tallahassee mayor took illegal gifts and picketed campaign money.

Federal prosecutors dismissed the corruption charges after Gillum was acquitted on one count, with the jury hung on the remaining charges.

Markus also represented Tom Grady, a Naples, Florida-based attorney who was accused of obstructing waters in the Florida Keys, according to Naples News.

In January 2014, Grady filed applications with state agencies to build a dock and two boat lifts, but the U.S. government claimed federal permits were necessary.

Prosecutors alleged the dock and two boat lifts violated the Rivers and Harbors Act of 1899, which barred any bridge or dam from being built over some navigable waters. A jury in 2021 found him not guilty of the violations.

As Epstein's death and previous criminal cases were brought back into the spotlight, Markus has made an effort to get Maxwell out of jail.

Maxwell in late July filed a brief with the Supreme Court asking justices to consider her appeal, which seeks a ruling on Jeffrey Epstein's non-prosecution agreement signed in 2007. The agreement states that "the United States also agrees that it will not institute any criminal charges against any potential co-conspirators of Epstein."

Maxwell argued that the agreement would have prevented federal prosecution in New York.

EPSTEIN GRAND JURY MATERIALS WON'T BE RELEASED AFTER FEDERAL JUDGE DENIES DOJ REQUEST TO UNSEAL

Markus has also, so far, successfully prevented the disclosure of grand jury transcripts in Maxwell's sex trafficking case.

"Jeffrey Epstein is dead. Ghislaine Maxwell is not," her attorney wrote. "Whatever interest the public may have in Epstein, that interest cannot justify a broad intrusion into grand jury secrecy in a case where the defendant is alive, her legal options are viable, and her due process rights remain."

A federal judge on Monday denied the Department of Justice's request to release the grand jury material, stating the documents do not contain "significant, undisclosed information about [their] crimes, or the investigation into them."

Criminal defense attorney Mark Eiglarsh, who knows Markus, told Fox News Digital that Maxwell's attorney "seems to understand what many high-profile lawyers don't."

"He's extremely brilliant, dedicated, passionate, zealous, experienced, and extremely humble. He seems to understand what many high-profile lawyers don't, and that is his ego is not his amigo," Eiglarsh said. "He does not shy away from a challenge. And boy, does he have a challenge here. Getting the Supreme Court to take this case at all is going to be extremely challenging. But then to zealously argue and effectively get them to embrace this case and his point of view, he's probably one of the only of few attorneys who could ever pull that off."

Fox News' Digital's Michael Ruiz and Ashley Oliver contributed to this report.