MINNEAPOLIS • After a wave of resignations decimated the Minnesota U.S. Attorney’s office, the federal government has tried to offset the staffing crunch with a novel strategy: deploying military lawyers to temporarily serve as assistant prosecutors.

That method now faces a legal test over whether these lawyers can prosecute civilians in court cases that have no ties to the U.S. military.

The challenge has been raised in a federal case against Minneapolis resident Paul Johnson, who’s charged with assaulting, resisting or impeding law enforcement.

His attorney, Kevin Riach, counters that agents brutalized Johnson during his arrest in January. Riach has argued that using military lawyers to prosecute civilians runs afoul of the 1878 Posse Comitatus Act, which blocks federal troops from enforcing laws against civilians except under narrow circumstances.

He is seeking the removal of the military lawyer assigned to prosecute Johnson, Michael Hakes-Rodriguez.

“There is no plausible reason a U.S. Army Judge Advocate [JAG] should be prosecuting Mr. Johnson in a Minnesota court,” Riach wrote in a brief.

While JAG lawyers historically have prosecuted crimes with a clear military connection, experts say the way the Trump administration is deploying them to handle cases enters new legal territory with no clear-cut answer.

“It can really depend on how courts are interpreting the relevant legal provisions,” said Jason Marisam, a professor at Mitchell Hamline School of Law.

Twenty-five JAGs currently serve Minnesota’s U.S. Attorney’s Office. Similar deployments of military lawyers as special assistant U.S. Attorneys have been seen in Tennessee and Washington, D.C.

Should a judge rule in Riach’s favor, the potential removal of military lawyers from cases could bear significant implications for the U.S. Attorney’s office in the state. Since President Donald Trump began his second term, the office has seen a mass exodus of at least 31 of its 64 lawyers either quitting or retiring.

The departing attorneys cited concerns about ethics, political pressure and the new administration’s decision to make immigration a top priority, according to a Minnesota Star Tribune investigation. Their exit wiped out nearly half of the office’s criminal and civil teams, and most of its top managers. Five administrators also quit.

As a result, the office has seen an uptick in hastened plea deals and outright dismissals.

Eleven former military lawyers wrote in support of Riach’s argument in a court brief, saying they were re deeply concerned about the use of JAGs in cases with no link to the military. They said the practice sets a dangerous precedent and may even be unlawful.

“To civilians, it may appear the government is deploying the military to prosecute the cases that career Department of Justice attorneys would or could not,” the group wrote.

“That appearance is harmful to our civil-military relations because it suggests military-led law enforcement is the catch-all substitute for regular civilian constitutional due process.”

Marisam said critics can argue that using the military lawyers blurs the separation that the Posse Comitatus Act is meant to protect. But he said the government can counter that the lawyers are detailed to a civilian office while under civilian supervision — making the lack of a military connection to the cases irrelevant.

“It’s not clear to me what the answer is,” Marisam said.

Chris Keyser, a Minneapolis criminal defense attorney and judge advocate for the Army Reserves, said the matter poses a nuanced legal argument. He said the legality of using military lawyers in such a way likely will come down to the title of the JAGs.