Two men charged with the 1975 slaying of a Canadian woman on the Pine Ridge Indian Reservation can be tried together, a U.S. magistrate judge has ruled in denying their requests for separate trials in South Dakota.

John Graham, a former Yukoner, and Richard Marshall, of Rapid City, S.D., have pleaded not guilty to charges they committed, or aided and abetted the first-degree murder of Annie Mae Aquash, a Mi'kmaq from Pictou, N.S.

They're scheduled to stand trial together in Rapid City starting Feb. 24 — 33 years after her body was found in the Badlands near Wanblee, S.D.

Marshall was indicted in August, five years after Graham and Arlo Looking Cloud were initially charged.

Looking Cloud was convicted in 2004 for his role in Aquash's murder and sentenced to life in prison. He is co-operating with prosecutors in their case against Graham and Marshall.

Witnesses at Looking Cloud's trial said he, Graham and Theda Clarke drove Aquash from Denver in late 1975 and that Graham shot Aquash as she begged for her life.

Clarke, who lives in a nursing home in western Nebraska, has not been charged.

Graham has denied killing Aquash, but acknowledged being in the car from Denver.

Constitutional rights cited

Prosecutors accuse Marshall of providing the handgun and shells that Graham used to kill Aquash on orders from American Indian Movement leaders who suspected she was a police informant.

Lawyers for Graham and Marshall had filed motions for separate trials.

Graham's lawyer, John Murphy, argued his client's constitutional rights would be violated if the men are tried together because statements made by Marshall will incriminate both men. Marshall is not expected to testify, so can't be cross-examined, Murphy added.

Murphy also wrote that such statements would otherwise not be admitted in Graham's trial, and the two men would give defences that could hurt each other's case.

Marshall's lawyer, Dana Hanna, also argued that evidence would be included against his client if both men are tried together, but wouldn't be admitted if Marshall is tried separately.

Hanna also argued that the government has a stronger case against Graham, which would hurt Marshall's chances for a fair trial.

Federal prosecutors Marty Jackley and Bob Mandel wrote in their responses that the law allows Graham and Marshall to be tried together because they're charged with taking part in the same crime.

'Defences are not mutually antagonistic'

In her 44-page order, U.S. Magistrate Judge Veronica Duffy of Rapid City agreed after concluding the law does allow jurors to consider both men's cases together.

Neither defendant has demonstrated "the kind of severe or compelling prejudice necessary to warrant severance," she wrote.

"Specifically, the court concludes that the two defendants' defences are not mutually antagonistic, and that there is no basis to believe that the jury cannot or will not compartmentalize the evidence against each defendant or that the jury will become confused."

Some of the statements in question are general enough that they wouldn't hurt the other defendant, and other statements could be edited to prevent one man from incriminating the other, the judge concluded.

She ordered lawyers to submit any such redacted versions of written or recorded evidence at least 15 days before the trial so there's enough time to review them.