RAPID CITY - Prosecutors and possibly one defendant plan to ask for a delay in the case of the 1975 slaying of an American Indian Movement member, but the other defendant wants to proceed, according to court documents.

John Graham and Richard Marshall are scheduled to stand trial May 12 in Rapid City on federal charges they killed or aided and abetted the murder of Annie Mae Aquash on the Pine Ridge Indian Reservation.

U.S. District Judge Lawrence Piersol last week dismissed an aiding and abetting charge against Graham because neither he nor Aquash belonged to a federally recognized tribe, which is required for the U.S. to have jurisdiction. Both are from Canadian tribes.

Piersol wrote that it's likely the other two remaining charges against Graham would be dismissed, though the state of South Dakota could charge him.

The government has appealed the dismissal to the 8th U.S. Circuit Court of Appeals, as well as a 2003 charge that Piersol threw out in October.

Piersol scheduled a motions hearing for Tuesday that will likely determine how the cases against Graham and Marshall proceed.

U.S. Attorney Marty wrote that the government believes Piersol has the authority to split the Graham and Marshall cases and try them separately, but the government and Marshall expected to file a request for a 60-day delay.

"Piecemeal litigation in this matter at this time will not serve the interests of justice or judicial economy, and there exist no speedy trial issues," Jackley wrote.

Marshall, a Lakota from Pine Ridge, was indicted in August, five years after Graham and Arlo Looking Cloud were charged.

Looking Cloud, also a Lakota from South Dakota who was living in Denver, was convicted in 2004 for his role in Aquash's murder and sentenced to life in prison. He's now a government witness.

Graham is from the Tsimshian Tribe in the Yukon and fought his return in British Columbia for more than four years before he was extradited in December 2007. Aquash was a member of Mi'kmaq Tribe of Nova Scotia.

Graham's lawyer, John Murphy, wrote in court documents that he doesn't care if Graham and Marshall are tried together but wants Graham's case to proceed May 12.

"Graham should not be prejudiced by being denied his right to a speedy trial because of the government's tactical decision to appeal count three at this time," Murphy wrote.

The prosecution theory is that Marshall gave a .32-caliber revolver and shells to Graham, Looking Cloud and Theda Clarke when they stopped by Marshall's house with Aquash hours before Graham shot her because AIM leaders suspected her of being a government informant.

Clarke, who lives in a nursing home in western Nebraska, has not been charged, though she is now listed as a material witness.

Her lawyer filed a motion Monday to quash the subpoena calling for her to testify on grounds she's incompetent.

Reasons cited in a memorandum and attached documents from doctors: Nelson is 84 and wheelchair bound; had a stroke; has dementia, diabetes, hypertension, hyperlipidemia, anxiety, depression, arthritis, impaired short- and long-term memory; is on numerous medications that can impair her memory; and suffers from "sundowning," which can cause confusion as she tires.