The federal investigation into an FBI agent's apparent firing of gunshots at Robert "LaVoy" Finicum and the alleged FBI tampering with evidence at the scene has gone to a grand jury.

Assistant U.S. Attorney Charles Gorder Jr. revealed the grand jury hearing in court papers Thursday explaining the government's desire to keep its memorandum about the inspector general's investigation into the FBI's handling of the Jan. 26 shooting out of the hands of defense lawyers.

"The Declaration provides details of an ongoing investigation by the United States Department of Justice, Office of Inspector General, and concerns matters occurring before the grand jury protected from disclosure,'' Gorder wrote to the court. "The Declaration more fully describes to the Court alone the nature of the material which is the subject of defendants' motion to compel and which the government contends should be denied from discovery.''

Gorder had previously asked U.S. District Judge Anna J. Brown to allow the criminal division's chief prosecutor in the U.S. Attorney's Office to file a memo under seal and only with the judge concerning the investigation of the FBI agents.

Defense lawyers in the Oregon standoff case have asked the judge to compel the government to turn over the investigative records regarding the FBI's alleged misconduct.

Late Wednesday, Brown said she'd allow prosecutors to file the memo under seal, but ruled it must be shared with defense lawyers. She said, however, that she would allow the government to make further argument why it shouldn't be shared with the defense.

That led to Gorder's expanded legal brief, noting the federal investigation is before a grand jury. Grand juries typically review investigations to determine whether to return criminal indictments.

Defense lawyers have argued that prosecutors must share any evidence that could benefit the defense, including any material that could damage the credibility of a prosecution witness. Federal prosecutors counter that they won't call law enforcement officers involved in the investigation as witnesses in the case, according to court records.

A federal grand jury indicted Ammon Bundy, the leader, and 25 co-defendants on a federal charge of conspiring to impede federal works at the Malheur National Wildlife Refuge during the 41-day occupation that ran from Jan. 2 through Feb. 11. Four have pleaded guilty to the conspiracy charge and one more is expected to do Thursday.

A trial for many of the remaining defendants is set for Sept. 7. Ammon Bundy has said the occupation was held to protest the return to federal prison of two Harney County ranchers and federal control of public land.

Bundy and other key figures were arrested as they were driving from the refuge to a community meeting in John Day on Jan. 26. Finicum, the occupation spokesman, evaded the police stop on U.S. 395 and swerved his truck into a snowbank to avoid an FBI and state police roadblock.

As he emerged from the truck, two shots were fired from an FBI agent with the Hostage Rescue Team, though none of the team members admitted to discharging their firearms, the Deschutes County sheriff alleges.

Oregon investigators concluded that one agent fired twice at the truck, hitting it in the roof and missing on the second shot. A state trooper later described to investigators seeing two rifle casings in the area where the agents were posted. Detectives investigating didn't find the casings, police reports indicated.

Updated June 24, 2016: Defense lawyer Per C. Olson replied to Gorder's filing, saying federal law allows for the court to authorize disclosure of a grand jury matter if it's connected with a judicial proceeding. Olson urged the court to accept the government's memo under seal, but allow defense lawyers access to it.

Ruling by U.S. District Judge Anna J. Brown on Fri., June 24, 2016 (U.S. District Court database)

Gorder files a response.

Judge Brown rules prosecutors haven't met the bar to file the document only with the court, so must file it sealed, and share it with defense lawyers.

The practice of filing legal briefs out of the eye of one party in a pending criminal proceeding, the judge wrote, is "strongly disfavored.''

-- Maxine Bernstein

mbernstein@oregonian.com

503-221-8212

@maxoregonian