A U.S. judge on Friday blocked subpoenas issued in a criminal investigation targeting Federal Reserve Chair Jerome Powell, agreeing with Powell that the probe was an improper attempt to pressure the central bank into cutting interest rates.

The investigation is led by U.S. Attorney Jeanine Pirro, appointed by former President Donald Trump, and concerns alleged cost overruns in renovations at the Fed’s Washington headquarters.

Chief U.S. District Judge James Boasberg ruled that the subpoenas were issued for an improper purpose and are therefore legally invalid. “The Government has offered no evidence whatsoever that Powell committed any crime other than displeasing the President,” the judge wrote, adding that the investigation appeared intended to intimidate Powell.

Following the ruling, Pirro announced that the Department of Justice will appeal the decision. Speaking at a news conference, she accused the judge of shielding Powell from scrutiny, stating: “As a result, Jerome Powell today is now bathed in immunity.”

The subpoenas had sought documents related to renovations of two historic Fed buildings and Powell’s July 2025 testimony before the Senate Banking Committee. Powell has defended the spending, describing it as necessary, and has hosted lawmakers and former President Trump on tours of the project.

The case leaves unresolved questions over Powell’s leadership and the broader political pressure from Trump, who has repeatedly criticized Powell for not cutting interest rates more aggressively amid ongoing inflation concerns.

Judge Boasberg’s decision emphasized that a “mountain of evidence” suggests the investigation’s true aim was to pressure Powell into lowering rates or resigning, rather than addressing legitimate criminal concerns.