The Justice Department said Thursday that then-U.S. Attorney Alexander Acosta exercised “poor judgment" while brokering a 2008 plea deal to end a federal probe into billionaire sex offender Jeffrey Epstein, but did not find any evidence of professional misconduct on Acosta's part. 

The Department of Justice’s Office of Professional Responsibility (OPR) released an executive summary of a report on the matter Thursday. Nebraska GOP Sen. Ben Sasse, who pushed the DOJ to open their investigation in February 2019, was briefed by the department on the conclusion of the probe and the findings of the executive summary on Thursday, Sasse spokesperson James Wegmann told Fox News. 

EX-ABC NEWS STAFFER SUES DISNEY-OWNED NETWORK OVER LEAKED JEFFREY EPSTEIN TAPE: REPORT

Sasse slammed the completion of the investigation, saying "justice has not been served" and demanded that the full findings of the internal review be released to the public. 

The Justice Department said Thursday that then-U.S. Attorney Alexander Acosta (left) exercised “poor judgment" while brokering a 2008 plea deal to end a federal probe into billionaire sex offender Jeffrey Epstein (right).

"Letting a well-connected billionaire get away with child rape and international sex trafficking isn’t ‘poor judgment’ – it is a disgusting failure. Americans ought to be enraged," Sasse said in a statement. 

He added: "Jeffrey Epstein should be rotting behind bars today, but the Justice Department failed Epstein’s victims at every turn. The DOJ’s crooked deal with Epstein effectively shut down investigations into his child sex trafficking ring and protected his co-conspirators in other states. Justice has not been served. The full report needs to be released to the public. OPR might have finished its report, but we have an obligation to make sure this never happens again."

The investigation concludes a 21-month-long probe by OPR into a non-prosecution deal Acosta and other department attorneys worked out for Epstein when Acosta was U.S. attorney for the Southern District of Florida. 

JEFFREY EPSTEIN ACCUSER STATES FOUNDATION FOR VICTIMS OF SEXUAL ABUSE

At the time, the wealthy financier Epstein was facing a federal indictment and possible life imprisonment for a sex scheme involving nearly 80 possible victims, many of them underage girls

Rather than facing prosecution for federal sex trafficking charges,  Acosta's "sweetheart deal" allowed Epstein to plead guilty to two felony prostitution charges in state court instead. The deal was also kept a secret from Epstein's alleged victims, likely in an attempt to prevent them from objecting to his sentence. 

Epstein ultimately served only 13 months in jail and registered as a sex offender. 

“While OPR did not find that Department attorneys engaged in professional misconduct, OPR concluded that the victims were not treated with the forthrightness and sensitivity expected by the Department," the DOJ said in a statement. 

"OPR also concluded that former U.S. Attorney Acosta exercised poor judgment by deciding to resolve the federal investigation through the non-prosecution agreement and when he failed to make certain that the state of Florida intended to and would notify victims identified through the federal investigation about the state plea hearing.”

NANCY GRACE RIPS 'DELUSIONAL' CAMPAIGN TO RELEASE GHISLAINE MAXWELL FROM JAIL

The DOJ opened the investigation into their attorneys after Sasse raised questions about their conduct following a report by the Miami Herald. 

The Florida news outlet released an explosive report earlier last year that alleged the government granted leniency to Epstein because of his immense stature and wealth, and also immunized from prosecution his co-conspirators, while also concealing the terms of the non-prosecution deal from Epstein’s victims. 

"After examining the full scope and context of the government’s interactions with victims, OPR concludes that the government’s lack of transparency and its inconsistent messages led to victims feeling confused and ill-treated by the government; gave victims and the public the misimpression that the government had colluded with Epstein’s counsel to keep the NPA secret from the victims; and undercut public confidence in the legitimacy of the resulting agreement," the executive summary of the DOJ's report, obtained by Fox News, said.  

"The overall result of the subjects’ anomalous handling of this case understandably left many victims feeling ignored and frustrated and resulted in extensive public criticism. In sum, OPR concludes that the victims were not treated with the forthrightness and sensitivity expected by the Department." 

Epstein was arrested again in July 2019 on federal sex trafficking charges in Florida and New York. 

Acosta, who was by then President Trump's labor secretary, resigned from the administration after renewed scrutiny on the former sex trafficking case over 10 years prior. 

Epstein was found hanging in his Manhattan jail cell from an apparent suicide in August 2019. 

CLICK HERE FOR THE FOX NEWS APP

Fox News' Jake Gibson contributed to this report.