The parents of Alex Pretti, a U.S. citizen and ICU nurse who was fatally shot by immigration officers in Minneapolis nine months ago, slammed the federal government and demanded the release of all the evidence related to their son’s death.

Michael and Susan Pretti said at a news conference Tuesday that the federal government has kept them in the dark for 275 days — even after they sent a letter to Attorney General Todd Blanche over the summer “begging for basic information the law affords,” including the identities of the officers involved in the shooting.

“At every turn, they have ignored us, misled us and shielded Alex’s killers,” Michael Pretti said.

“We want our son’s killers to be brought into justice once and for all,” Susan Pretti said. “We are here begging for the Department of Justice to do what is right.”

Kiersten Pels, a spokesperson for the Department of Justice, told NBC News that communications between federal officials and victims’ families “do not typically occur” during an investigation.

“As is standard practice, communications with family members, if any, come at a later stage of a case, such as indictment, initial appearance, plea, trial, or sentencing,” Pels said in a statement. “The timing is consistent with how these types of investigations proceed.”

The Department of Homeland Security referred all questions to the FBI.

Tuesday’s news conference comes nearly a week after Hennepin County Attorney Mary Moriarty said the federal government stopped sharing information with Minnesota authorities who are investigating Pretti’s killing.

Moriarty’s office sued the Trump administration in March to compel federal officials to share key evidence pertaining to Pretti’s death and the shootings of Julio Cesar Sosa-Celis, a Venezuelan man who was wounded by an ICE officer, and Renee Good, who was fatally shot by another ICE officer.

The three Minnesota shootings took place in January, after the Trump administration deployed more than 3,000 immigration officers and agents to the state as part of “Operation Metro Surge,” the DHS’s largest immigration enforcement operation.

In July, Minnesota officials said the federal government was starting to turn over evidence in the cases, including police body camera video and hard drives containing statements. Moriarty said at the time that she expected to receive “all the evidence.”

That changed this month, according to Moriarty. In a statement last week, she accused the federal government of withholding evidence related to the fatal shootings of Good and Pretti and “obstructing our investigations for however long they can.”

“Our lawsuit was filed to gain access to all of the evidence and our efforts to obtain it will continue. We have filed our motion for summary judgment to bring an end to the case and secure the evidence to which we’re entitled,” Moriarty said. “The federal government responded with a motion to dismiss; their aim is clear.”

In the motion filed by DOJ attorneys at the U.S. District Court in Washington, D.C., last week, the federal government argued it has the authority to decline sharing information with state authorities if no formal legal proceedings are underway.

The Trump administration has previously suggested that state prosecutors have no jurisdiction to investigate federal officers, while Minnesota officials have said the federal government can’t be trusted to investigate itself.

“This is not normal. This is not justice. It is morally wrong,” Michael Pretti said at the news conference. He decried that the lack of cooperation between federal and local authorities in investigating his son’s killing “is just baffling, disappointing and reprehensible.”

Steven L. Schleicher, a lawyer for the Prettis who was also at the news conference, said his clients are entitled to see any evidence about the shooting under the Crime Victims Rights Act.

“How is it possible that the Department of Justice is not sharing evidence,” Schleicher said. “What are they hiding?”

During his confirmation hearing in July, Blanche was asked about his commitment to sharing information on the ICE-involved shootings in Minnesota with state officials. He said he expected the investigations into those cases to be run as usual, adding that “the definition of full cooperation can be disputed.”

Videos showing Alex Pretti’s killing haunt his family every day, his parents said. At the same time, according to them, those images were crucial in contradicting the Trump administration’s narrative of the shooting.

“The federal government went on TV and lied about Alex. They tried to slander his memory to cover up their crime,” Susan Pretti said. “Not only was it wrong, it was shameful, unfair, unacceptable. We want to clear our son’s name.”