FILE PHOTO: Former FBI Director James Comey is sworn in prior to testifying before a Senate Intelligence Committee hearing on Russia's alleged interference in the 2016 U.S. presidential election on Capitol Hill in Washington, U.S., June 8, 2017. REUTERS/Jonathan Ernst/Files

By Andrew Goudsward

WASHINGTON (Reuters) -A U.S. judge found on Monday there is evidence of misconduct in how a federal prosecutor closely aligned with President Donald Trump secured criminal charges against James Comey, and ordered that grand jury materials be turned over to the former FBI chief's defense lawyers.

Alexandria, Virginia-based U.S. Magistrate Judge William Fitzgerald found that Lindsey Halligan, the Trump-appointed U.S. attorney leading the case, may have made significant legal errors in presenting evidence and instructing grand jurors who were weighing whether to charge Comey - mistakes that could have tainted the case.

"The record points to a disturbing pattern of profound investigative missteps, missteps that led an FBI agent and a prosecutor to potentially undermine the integrity of the grand jury proceeding," Fitzgerald wrote in his ruling.

Comey is one of three prominent critics of the Republican president to have been hit with criminal charges by Trump's Justice Department in recent months. Trump critics have described the charges as a part of a campaign by the president to chill opposition. Comey pleaded not guilty after being charged in September with making false statements and obstructing a congressional investigation.

A different judge previously expressed skepticism about the legality of Halligan's appointment, while other courts have raised alarm about political motivations in Justice Department investigations and grand juries have rejected cases tied to Trump's police surge in Washington.

Halligan had not worked as a prosecutor before Trump appointed her in September. She had primarily practiced real estate law and represented Trump in civil litigation.

A Justice Department spokesperson declined to comment on the judge's decision.

Prosecutors previously argued in court filings that Comey's claims about the grand jury were speculative and did not justify disclosure of records.

WAVE OF TARGETS

Comey has sought to get the charges against him dismissed, saying the prosecution resulted from Trump's "personal spite" against him over his criticism of the president and his leadership of an investigation into contacts between Trump's 2016 campaign and Russians.

Trump has threatened to imprison rivals since he first ran for president in 2015. Comey's indictment was followed by indictments of two other prominent Trump critics - his former national security adviser John Bolton and New York state Attorney General Letitia James. The charges in these three cases breached a long-standing Justice Department practice of political independence in criminal investigations.

Prosecutors allege that Comey lied to a Senate committee in 2020 when he said he stood behind prior testimony that he had not authorized anyone at the FBI to be an anonymous source in news reports about investigations into Trump and his 2016 rival, Democrat Hillary Clinton.

Fitzgerald said he would order prosecutors to turn over grand jury materials to Comey's defense for use in a potential future legal motion to have the charges dismissed.

Grand jury materials are typically protected by strict secrecy rules. Fitzgerald acknowledged that disclosure to the defense was an "extraordinary remedy," but found that Comey had shown a specific need for the records.

"The Court finds the record in this case requires the full disclosure of grand jury materials," the judge wrote.

"In so finding, the Court recognizes this is an extraordinary remedy, but given the factually based challenges the defense has raised to the government's conduct and the prospect that government misconduct may have tainted the grand jury proceedings, disclosure of grand jury materials under these unique circumstances is necessary to fully protect the rights of the accused."

Fitzgerald's ruling catalogs a series of what the judge described as investigative blunders in the investigation. These include prosecutors' decision to review evidence the FBI seized years earlier without securing a new warrant and allowing an FBI agent to testify to the grand jury even though the agent may have been exposed to material shielded by attorney-client privilege, a legal doctrine that protects legal advice between lawyers and their clients.

The judge also found that Halligan made statements to grand jurors harmful to Comey's legal rights.

(Reporting by Andrew Goudsward, Editing by Scott Malone, Franklin Paul, Chizu Nomiyama and Will Dunham)