A group dedicated to freeing innocent prisoners is casting new doubt on the guilt of a drifter convicted decades ago in a serial killer case that had gripped Minneapolis.

The Minnesota Innocence Project said new DNA testing in the high-profile murders of three American Indian women in the 1980s found no link to the convicted man, Billy Glaze, who is serving three life sentences for the crimes. The tests of 39 items found at the murder scenes, including bodily fluids, clothing and other items, instead implicate another man — a convicted Minnesota rapist, the attorneys contend.

They are seeking a new trial for Glaze in court papers filed Tuesday. They would not identify the newly implicated suspect, though they said they have provided Hennepin County prosecutors with test results.

Deputy Hennepin County Attorney Dave Brown said authorities were still reviewing the voluminous filing from the Innocence Project attorneys, but his office has been communicating with the group.

"There's nothing that we've seen through the years, as we've reviewed these claims, that suggests to us that anyone other than Billy Glaze is the one that did these brutal sexual mutilations and murders," Brown said. "On the other hand, we'll take a careful look at their claims."

Glaze, now 70, has spent more than 25 years behind bars in connection with the murders. A jury found him guilty of first- and second-degree murder in the bludgeoning deaths of Kathy Bullman, 19, Angeline Whitebird-Sweet, 26, and Angela Green, 21. All three were found nude or mostly nude with their bodies positioned in ways that suggested a serial killer. The cases prompted intense media attention and public outcry, including allegations that police hadn't been aggressive in investigating crimes against Indians.

Gladys Genschow, Whitebird-Sweet's older sister, said she was shocked to learn Tuesday night that Glaze's conviction is being questioned after all these years. "I thought they had him," she said.

But if the evidence shows he didn't murder the three women, Genschow said she is glad they are reopening the case. "They need to find the right person," she said. But reopening the case will reopen painful memories. "I would lay awake at night, and I could hear my mother crying," Genschow said, explaining she would have to tell her mother, who is now 79 and has suffered several strokes, about the latest development.

Mavis Kingbird, Whitebird-Sweet's younger sister, remembers sitting in the murder trial, trying to avoid Glaze's eyes when he stared at her. "My sister and I look alike," she said. "If they have the wrong person in prison, that's not right. … It's kind of scary that someone else who could have done this is still out there running free."

Glaze's 1989 conviction was based largely on testimony from witnesses and jail inmates. Prosecutors also presented a note that Glaze had purportedly written in jail saying, "I killed them. I was mad at them."

Innocence Project attorneys say the witness testimony was unreliable and the physical evidence — including the note — didn't prove him guilty. Most importantly, they say, no biological evidence linked him to the crimes.

"There is not a single item that has come up that matches Billy," said Ed Magarian, a partner at the firm of Dorsey & Whitney who is working on the case.

"Through no fault of its own, the state did not have the DNA evidence available to them at the time that we do today," Minnesota Innocence Project managing attorney Julie Ann Jonas said.

The group is part of the national Innocence Network, which is dedicated to assisting prisoners who could be proven innocent through DNA testing or other evidence. Since 1989, the network has helped free 1,370 people, 316 of them through DNA testing.

The attorneys said Glaze, who is serving his prison sentence in Delaware, was not available for comment and suffers from mental illness.

A city watching

The bodies of the women were found between July 1986 and April 1987 in three locations frequented by transients in Minneapolis.

The murders produced a frenzy of anger in the city after the third victim was found. Members of the Guardian Angels and the American Indian Movement (AIM) at one point patrolled the streets, distributing leaflets warning the murderer that they were out to find him.

Weeks later, Glaze emerged publicly as a suspect.

Born in Georgia, he had drifted around the country. Law enforcement in New Mexico arrested him during a traffic stop in mid-1987 and discovered he was wanted for violating parole on an acquaintance rape conviction and was a suspect in the killings.

At Glaze's trial, several witnesses claimed to have seen him with the women before their murders, some placing him near the crime scenes. Some said Glaze made violent sexual remarks about Indian women. A transient testified that he saw Bullman's killed.

But experts testified that some of the blood found where Whitebird-Sweet, a mother of three, was killed could not have come from her or Glaze.

A jail inmate testified that in the fall of 1987, Glaze wrote a note saying, "Don't let anyone here [sic] you, but not to let anyone know. I killed them. I was mad at them."

The jury deliberated for 35 ½ hours over four days before finding Glaze guilty of killing the women while sexually assaulting them.

Glaze told a judge before sentencing that the witnesses against him were liars: "I'm not the serial killer … I ain't never … said that about Indian women," he said, according to a Star Tribune report on the trial. "But do what you have to do."

Years of work by project

Glaze contacted the Minnesota Innocence Project about a decade ago. It took attorneys almost three years to confirm that evidence still existed.

They learned that in 2003, the Hennepin County attorney's office had asked the state Bureau of Criminal Apprehension to conduct a DNA test of a bloody jacket found a half-mile from Whitebird-Sweet's body.

"There was no reason to conduct that testing (especially at taxpayer's expense) unless the State had doubts about whether the State had actually convicted the right man," their filing said.

Brown would not comment Tuesday on specific evidence in the case but said the office has been reviewing evidence, including more than 3,600 of its own files, for DNA evidence. "We have an ongoing duty to see that justice is done," he said.

In the Glaze case, Brown pointed out, the evidence was collected from three scenes frequented by transients. "The difficulty in analyzing the DNA evidence that they are presenting is that these scenes were chaotic," he said.

The 2009 DNA testing of sperm collected from a vaginal swab of Green excluded Glaze, but when attorneys persuaded the FBI to agree to run the DNA through a national database of millions of offenders in 2012, it came up as a match to another Minnesota man.

In April of this year, DNA testing of a then-fresh cigarette butt collected a few feet from Whitebird-Sweet's body also excluded Glaze and revealed a match to the same Minnesota man.

Innocence Project attorneys found the other man had been frequently jailed but was out at the time of each murder. He used to hang out at the same establishments as the victims, the filing Tuesday said.

The attorneys also challenge many of the trial witnesses and evidence, arguing:

• One man recanted his testimony about seeing Glaze with Bullman. He had testified after discussing the case with his probation officer, the document said.

• Others who testified that they saw Glaze near the Green crime scene were relatives or close friends of an Indian woman who had been raped and strangled six weeks before Bullman's murder.

• The transient who testified that he had witnessed Bullman's murder claimed to have witnessed more than 60 murders while in prison.

• The jail inmate who produced Glaze's note later admitted he was looking for a "deal."

False testimony, confessions

Innocence Project attorneys acknowledge that about 10 years ago, Glaze confessed to a slew of murders in California, though he was never prosecuted because his details didn't match the crimes, the attorneys said they were told. It was also the only time he told authorities that he had committed the Minnesota murders. They believe the confessions were false.

Glaze was "branded a serial murderer 27 years ago in the press, and then 25 years ago by his conviction," the filing says. "Justice can only be served by correcting this injustice as quickly as possible."

They say the man they believe is the killer is free and still in Minnesota.