Two U.S. Park Police officers who fatally shot Virginia resident Bijan Ghaisar are trying to move their case from Fairfax County Circuit Court to federal court, where they would have federal immunity defense from charges filed last month at the state level.

Fairfax County Commonwealth’s Attorney Steve Descano said in an interview Tuesday that he anticipated the removal motion and had been working with the Virginia Attorney General to prepare “strategic responses so that we can ensure a fair and thorough trial occurs.”

“Although this is another obstacle, I want to reassure the Ghaisar family, as well as our community and everyone following this case, that I will not give up. I’m committed to seeking justice for Bijan,” Descano told DCist/WAMU.

Exactly three years ago, officers Alejandro Amaya and Lucas Vinyard pursued 25-year-old Ghaisar after he left the scene of a minor traffic accident. Video released from Fairfax County Police Department showed Ghaisar stopped twice and then pulled away after the officers approached him with guns drawn. The third time Ghaisar stopped his vehicle and pulled forward, one officer fired multiple shots, and a second officer approached and shot as well. Two more shots were fired after Ghaisar’s car fell down an embankment.

Following an FBI investigation, federal prosecutors did not press charges against Amaya and Vinyard. However, Descano and his predecessor Raymond Morrogh independently investigated the case. In October, Descano announced that a grand jury had indicted the pair for involuntary manslaughter and reckless discharge of a firearm. Amaya and Vinyard turned themselves in and were released on bond on Oct. 19, on condition that they not use their police powers, not possess firearms, and not leave Virginia.

On Tuesday, lawyers for the two officers filed to move the case to federal court, saying they were performing their duties as U.S. Park Police officers under the U.S. Department of the Interior. In a notice of removal for Amaya, attorney Travis Tull wrote that Ghaisar drove erratically, including speeding, weaving outside his lane, entering a lane of oncoming traffic, and running stop signs: “The officers had become concerned that Ghaisar’s erratic driving behavior appeared to be escalating, thus creating a risk of death or serious bodily [harm] to the officers themselves, to other motorists, to pedestrians, or the public in general.”

Attorney Daniel Crowley, representing Vinyard, wrote that “In pursuing and attempting to apprehend Ghaisar, and while attempting to protect Officer Amaya from the threat of serious bodily harm, Officer Vinyard was clearly performing acts he was authorized to do as a federal police officer.”

Crowley argued the two Park Police officers were entitled to immunity under the Supremacy Clause of the U.S. Constitution. He referred to Kentucky v. Long, a case in which federal judges determined a state court had no jurisdiction if a federal agent was performing an act that he was authorized to do and did not do “more than what was necessary and proper.”

A lawyer for Ghaisar’s family could not be reached for comment.

Ghaisar’s family has filed a separate $25 million federal civil lawsuit against the United States for excessive use of force. That trial was set to begin this week, but U.S. District Judge Claude M. Hilton postponed it after the officers were indicted in Fairfax, the Washington Post reported.