Prosecutors dropped federal charges Wednesday against one of two men accused in the 1975 slaying of a fellow American Indian Movement activist on a South Dakota reservation, opening the door for the case to move to a state court.

The decision settled a question of whether the federal court had jurisdiction over the case against John Graham, who is from the Tsimshian Tribe in Canada’s Yukon Territory.

Graham and Richard Marshall were charged in federal court with killing or aiding the murder of Annie Mae Aquash on the Pine Ridge Indian Reservation. U.S. District Judge Lawrence Piersol agreed to throw out the indictment against Graham after a request from prosecutors. Graham still faces state charges.

Aquash, a member of Mi’kmaq Tribe of Nova Scotia, was killed by a gunshot wound to the head. The 30-year-old was among the Indian militants who occupied the village of Wounded Knee in a 71-day standoff with federal authorities in 1973 that included an exchange of gunfire with agents who surrounded the village.

State prosecutors said Graham and two other AIM members – Arlo Looking Cloud and Theda Clarke – drove Aquash from Denver to Rapid City, where she was held against her will and questioned about whether she was an informant. Prosecutors have said she was not working with the government, and allege that Graham raped Aquash and later fatally shot her.

Piersol earlier dismissed one of the counts against Graham because it didn’t show that either Graham or Aquash belonged to a federally recognized American Indian tribe. Tribal status gives the federal government jurisdiction in the case.

Graham’s lawyer, John Murphy, said he was pleased with Piersol’s order and criticized prosecutors for waiting until the last minute to ask for dismissal. Graham and Marshall were scheduled to stand trial later this month in Rapid City, S.D.

“This legal journey has been incredibly expensive, time consuming, and, most importantly, has taken a toll on Mr. Graham,” Murphy said. Appeals in the case lasted a year and Graham has been in jail for two years, the defense attorney said.

During a court hearing last year, Piersol told federal prosecutors that unless they had new evidence showing jurisdiction, it would be unlikely that the federal charges against Graham would stick.

An appeals panel upheld that ruling.

In September, while the federal case was pending, Graham and another former AIM member, Thelma Rios, were charged in state court. Graham faces one count of felony murder in relation to kidnapping, one count of felony murder in relation to rape and one count of premeditated murder in Aquash’s slaying. Rios is charged in state court with one count of felony murder in relation to kidnapping and one count of premeditated murder. She has pleaded not guilty.

Federal prosecutors said in a statement that the government is unlikely to prevail on the issue of American Indian status and dropping the charges is “in the interest of justice.” The ruling is not expected to affect proceedings for Marshall, who has pleaded not guilty. His trial is still set to begin in Feb. 16.