PIERRE - After three trials, the search for answers continues in the late 1975 slaying of an American Indian Movement activist, an incident that epitomizes the clashes between federal agents and Indian activists.
The daughters of Annie Mae Aquash and authorities have long held that Aquash died because American Indian Movement leaders ordered her death out of suspicion that she was a government spy.
Now, the death of a key potential witness in the case could further complicate the investigation of a crime that still stirs passions in Indian Country.
Observers saw Thelma Rios, another former activist, as someone who could answer lingering questions about the case and identify others involved. But the 65-year-old Rios' death earlier this month from lung cancer deprives prosecutors of a witness who has said she heard others saying Aquash should be killed.
"If Rios identified just one of them, it would be a link into the leadership," said Paul DeMain, an Indian journalist who's long researched the Aquash case.
South Dakota Attorney General Marty Jackley said he remains confident in what he called an open investigation.
"Not every piece of evidence that a prosecutor has gets in for a variety of reasons," Jackley said. "Those evidentiary issues, I feel, don't affect the overall resolution of the case."
Authorities believe three activists killed Aquash on the orders of someone in AIM's leadership. Witnesses said the three activists took Aquash from Denver, where she was living in November 1975, to Rapid City and eventually to the Pine Ridge reservation, where she was shot with a .32-caliber pistol and left to die.
One of the activists, Arlo Looking Cloud, was convicted of murder in 2004. Another activist, John Graham, was found guilty of felony murder in December. The third, Theda Clark, has never been charged.
Rios is believed to have called someone in Denver to have Aquash brought to Rapid City. Just before Graham's trial, Rios pleaded guilty to having a role in Aquash's kidnapping. As part of the plea, she signed an agreement with a summary of what she knew about the crime.
The statement includes the following details:
·Rios overheard two people discussing informants "more than once." She was told by two people to relay the message that Aquash should be brought to Rapid City.
·She gave Clark access to her Rapid City apartment, where Aquash was allegedly taken by the three activists.
·She overheard two people discussing how "the b---- should be offed."
The names Rios mentioned were redacted in court documents. Jackley and Matt Kinney, one of Rios' attorneys, declined to disclose the names.
One witness at Graham's trial, Candy Hamilton, said she overheard Rios talking with three people linked to AIM in the past: Bruce Ellison, Lorelei DeCora and Madonna Thunder Hawk.
DeCora and Thunder Hawk did not return messages seeking comment. In an interview, Ellison said he doesn't remember having any conversations with Rios about the incident.
"I have no idea what Candy Hamilton's talking about, either," he said. "All I can say is she's got a great imagination."
But Rios' death means prosecutors will have to bring any future charges without a crucial witness.
Defendants at trial have the constitutional right to confront their accusers, said Chris Hutton, a criminal law professor at the University of South Dakota School of Law.
"If the government seeks to use statements that were made out of court, it has to figure out a way to be able to provide the defendant the opportunity to confront and cross-examine the witness," she said.
Jackley said he believed statements made in court, such as Rios' plea agreement, could be allowed into evidence at a future trial. Other things Rios told authorities outside the courtroom would likely require her to appear as a witness, he said.
For years, witnesses refused to come forward. But authorities began to make progress in the 1990s, and Graham and Looking Cloud were first indicted in federal court in 2003. Graham later had to be charged in state court.
Another former AIM activist, Richard Marshall, was acquitted of murder last April. Prosecutors alleged that he provided the pistol used to shoot Aquash.
Denise Maloney Pictou, Aquash's elder daughter, has said she believes others with responsibility for her mother's death remain at large.
Aquash, a member of the Mi'kmaq tribe of Nova Scotia, was 30 when she died. Her death came about two years after she participated in AIM's 71-day occupation of the South Dakota reservation town of Wounded Knee.
AIM was founded in the late 1960s to protest the U.S. government's treatment of American Indians and demand the government honor its treaties with Indian tribes. It gained national attention in 1972 when it took over the Bureau of Indian Affairs headquarters in Washington but has since faded from public view.