The parents of Alex Pretti, the 37-year-old nurse killed by federal immigration agents in Minneapolis earlier this year, accused federal officials of stonewalling them and shielding their son’s killers.

During a press conference on Tuesday, Michael and Susan Pretti made their first public remarks since their son’s death in January, calling for the Department of Justice to hold those involved in their son’s death accountable. The federal government has not provided them with meaningful information about the case, they said.

“At every turn, they have ignored us, misled us and shielded Alex’s killers,” said Michael Pretti. “We are a family who love this country. We trust in the institutions of this country. We believe in the rule of law – and that people should be held accountable through that law.”

Pretti, who worked at a veterans hospital, died on 24 January after being fatally shot by federal immigration agents. The Trump administration quickly painted Pretti as a domestic terrorist who was armed, and baselessly accused him of wanting to harm agents during Donald Trump’s immigration operations in Minnesota. They defended the agents and said Pretti had violently resisted.

Video footage of the incident contradicted the government account, and showed Pretti had a cellphone in his hand and did not brandish a weapon or attack agents before they shot him in the back as he lay in the street.

Pretti had no criminal record and had a license to carry the handgun he had holstered before agents removed the weapon and opened fire.

“The federal government went on TV and lied about Alex,” said Susan Pretti. “They tried to slander his memory to cover up their crime. Not only was it wrong, it was shameful.”

The couple spoke publicly after Todd Blanche, the US attorney general, and Dan Rosen, the top federal prosecutor in Minnesota, stonewalled them, they said. The Trump administration has argued that the state does not have the jurisdiction to investigate federal officers.

Rosen only agreed to meet with them in July after they had reached out for months, but the prosecutor declined to provide basic information about the status of the investigation, the couple said.

Minnesota officials recently said the federal government stopped sharing information with the state investigators looking into the deaths of Pretti and Renee Good, a 37-year-old who was fatally shot by an ICE officer as she attempted to drive her car away during a protest in January.

The couple said it had been a miserable year for their family and told CNN in an interview that they were only asking for justice.

“We’re not asking for anything other than accountability and [for] the Department of Justice and Dan Rosen to do their jobs,” Susan Pretti said. “Alex was murdered nine months ago. It’s difficult to get up every day, to function, to be a parent, knowing that your child is never coming home.”

In a statement to Reuters, the justice department said that “communications with family members, if any, come at a later stage ​of a case, such as indictment, initial appearance, ‌plea, trial, or sentencing. Those communications ‌do not typically occur during an investigation.”

The Associated Press and Reuters contributed