If Minnesota officials try to prosecute the federal agents who recently killed two people in Minneapolis, they’ll face steep obstacles from a century-old Supreme Court precedent — one that helped sink a similar case just a few years ago.

Minnesota officials have not explicitly said they will bring criminal charges against ICE and Border Patrol agents responsible for the deaths of Renee Good and Alex Pretti, but Mary Moriarty, the top local prosecutor in Minneapolis, has opened homicide investigations into both shootings. And Minnesota Attorney General Keith Ellison has strongly pushed back on claims that federal agents cannot be prosecuted.

“There is no exemption for federal officers. Nobody gets to commit a crime in Minnesota and be unaccountable for it,” Ellison said on cable news Tuesday night.

But state prosecutors would face significant hurdles.

The 2017 shooting of Bijan Ghaisar by two U.S. Park Police officers in a Northern Virginia neighborhood — and the protracted legal battles that followed — may be the best preview of what Minnesota officials can expect if they pursue criminal charges against federal immigration agents. And the same legal theory that stymied Virginia’s prosecution may also block Minnesota’s.