At least six career prosecutors in the Minneapolis U.S. Attorney's office — including Assistant U.S. Attorney Joe Thompson — have resigned as the office continues to face pressure to treat the investigation of the fatal shooting of a Minneapolis woman by an ICE officer as an assault on a federal officer case.

Thompson also previously served as the acting U.S. attorney for Minnesota; he was appointed by President Trump in June and served in the position until October. He resigned from the attorney's office along with Harry Jacobs, Melinda Williams, Thomas Calhoun-Lopez, Ruth Schneider and Tom Hollenhurst.

Two sources familiar with the matter tell CBS News the resignations stemmed from concern over a request to probe Good's widow — who was with her when they encountered the ICE agents — as well as the way that the case is being treated as an assault on a federal officer as opposed to a civil rights case. 

Thompson was the lead prosecutor in the Feeding Our Future case, a COVID-era $250 million scheme which targeted programs that were meant to feed schoolchildren. Since then he's charged defendants for allegedly defrauding housing and autism service programs, claiming that fraud in Minnesota has topped $9 billion, a figure which Minnesota Gov. Tim Walz has pushed back on.

The New York Times reported Tuesday that a number of people familiar with Thompson's decision said he also objected to federal investigators refusing to cooperate with Minnesota state agencies in investigating Good's killing. 

Doug Kelley, a former assistant U.S. attorney for Minnesota, says the move is a major blow to the credibility of the office moving forward.

"I've been practicing federal criminal law in this state for 51 years and this is the darkest day in 51 years as far as I can see for the rule of law in Minnesota," Kelley said. "If they feel the need to resign because of orders they have gotten that will violate their consciouses, to me it's a great statement on their part that this is not tolerable by them."

Since the massive fraud scandal, Mr. Trump has lashed out at Minnesota's large Somali-American community, as many of the Feeding Our Future defendants are of Somali descent. His administration cited the fraud scandal as impetus for deploying thousands of federal immigration agents to the Minneapolis area.

Walz called Thompson's resignation a "huge loss for our state."

"It's also the latest sign Trump is pushing nonpartisan career professionals out of the justice department, replacing them with his sycophants," Walz said on X.

Sen. Amy Klobuchar said on X that "these career public servants have served our state through multiple tragedies and critical investigations. We cannot allow prosecutors to be driven by politics. The family and loved ones of Renee Good deserve justice, not political attacks." 

Thompson also filed charges against Vance Boelter, the man accused of killing former House Speaker Melissa Hortman and her husband Mark, as well as shooting state Sen. John Hoffman and his wife Yvette, who survived. 

This is a developing story. Check back for details.