Officials in Minnesota have sued the federal government, claiming they were blocked from investigating three shootings involving federal agents during an immigration operation.

The lawsuit, led by Attorney General Keith Ellison, accuses the Department of Justice and Department of Homeland Security of withholding key evidence.

State investigators say cooperation from federal agencies was initially promised but later abruptly cut off, preventing access to witnesses, crime scenes, and materials.

The cases involve two fatalities and one injury, with conflicting accounts and ongoing federal internal reviews, CBS News has reported.

The lawsuit argues the federal government acted unlawfully and violated longstanding practices of cooperation with state authorities.