A judge on Monday threw out a key part of the federal government's case against indicted FBI Agent W. Joseph Astarita -- a 3D model that pinpointed where prosecutors suspect the agent was standing when he's accused of firing at the truck of Oregon occupation spokesman Robert "LaVoy" Finicum in 2016.

The representation of Astarita's position is based on "fuzzy smudges'' from an aerial FBI video and can't accurately support the placement of the agent at the scene, U.S. District Judge Robert E. Jones wrote in a 26-page decision.

The judge said he, therefore, won't allow a jury to see the full model at trial, unless there's separate eyewitness testimony that places the agent's position at the scene.

The ruling dealt a significant blow to the pending prosecution of Astarita, accused of falsely denying he fired two shots at Finicum or his truck on Jan. 26, 2016. The shots came as Finicum emerged from his pickup at a roadblock when police arrested the leaders of the armed takeover of the Malheur National Wildlife Refuge.

Document: Ruling by U.S. District Judge Robert E. Jones

The ruling followed a four-and-a-half day hearing in May.

Astarita, a member of the FBI's elite Hostage Rescue Team, has pleaded not guilty to three counts of making a false statement and two counts of obstruction of justice.

One bullet went through the truck's roof and the other went astray, investigators said. Moments later, two state troopers fatally shot Finicum as he was reaching inside his jacket. Investigators said he had a loaded handgun in an inner pocket.

The 3D shooting reconstruction by government expert Toby Terpstra put Astarita in a shooting position with a rifle shouldered and trained on Finicum's truck.

But the judge said the video images Terpstra used "were of such poor quality that I am unconvinced this methodology could accurately place the location of the individuals and the positions which they are posed in the model."

"The clear image of the model depicting defendant with his rifle shouldered and trained on Finicum's truck was not the product of a reliable methodology and involved excessive subjectivity,'' the judge wrote.

Without any evidence from other witnesses about where Astarita was standing at the time, Terpsta's model "may not be presented as an accurate representation of what is depicted in the FBI still frames that look like fuzzy smudges,'' he said.

The model, though, could be used to show the location of the law enforcement trucks at the scene because those were based on clear images captured by the aerial FBI video, the judge ruled.

Terpstra is a senior forensic animator at the Colorado-based company Kineticorp.

The judge did allow all of the other government experts to be called at trial, now set for July 24.

Though defense lawyers had poked holes in some of the other experts' methodology, the judge said those matters were for a jury to decide.

Jones will allow trial testimony from the government's audio-visual expert Frank Piazza, bullet trajectory experts, Oregon State Police forensic scientist Victoria Dickerson, Albuquerque forensic scientist Michael Haag and Deschutes County Sheriff's Deputy Kevin Turpen, who made a diagram of the scene.

"Though imperfect,'' their work passed scientific muster, the judge said, and could be subject to "rigorous cross-examination'' by the defense.

Turpen, an accident reconstructionist, took measurements at the scene of the shooting and made his own diagram, placing FBI agents and state troopers on the scene, but he acknowledged in court that he wasn't able to identify the agents or troopers' "precise locations'' at the time of the shooting.

Prosecutors may have a hard time supporting their case with witness testimony.

According to a grand jury transcript, Astarita's immediate supervisor on the FBI Hostage Rescue Team's blue squad, identified as only as B.M., testified that he didn't recall hearing gunshots when Finicum got out of his truck, although prosecutors said B.M. was standing beside Astarita.

Defense attorney David Angeli declined comment Monday afternoon, citing the upcoming trial date. Kevin Sonoff, spokesman for the Oregon U.S. Attorney's Office, also said prosecutors declined comment.

Defense lawyers had argued during last month's hearings that the government's reconstruction of Astarita's alleged shots weren't based on sound forensic methods.

"They come in and present this evidence as if it's precise. It's just not so,'' said Robert Cary, a well-known Washington, D.C.-based defense lawyer for Astarita. "It's presented as science and it's way dangerous.''

Prosecutors countered that they relied on multiple experts who used independent state-of-the-art forensic methods and all placed Astarita as the only one who could have fired the shot that struck the roof of Finicum's truck.

Piazza synchronized two videos from the scene - one taken by passenger Shawna Cox from inside Finicum's truck and the other from an FBI plane flying overhead about two miles away.

Before trial, there's the possibility that the government could offer a plea agreement, but a plea to a federal offense would end Astarita's federal law enforcement career.

-- Maxine Bernstein

mbernstein@oregonian.com

503-221-8212

@maxoregonian