Native American activist Leonard Peltier had a parole hearing Monday, his first in 15 years after being sentenced to life in connection to the 1975 killings of two FBI agents in South Dakota.

Mr Peltier, a member of the Turtle Mountain Chippewa tribe, was active in the American Indian Movement (AIM).

Tashina Banks Rama, who is Oglala Lakota and Ojibwe of the Leech Lake Band and the daughter of AIM co-founder Dennis Banks, told National Indigenous Times AIM began in Minneapolis in reaction to police brutality and other injustices.

"The American Indian Movement was a movement of men and women who were fighting to be recognised. They were fighting against police brutality that was taking place in at the time Minneapolis. The beginning of AIM was 1968… the environment of Minneapolis was really harsh for Native people," she said.

"The Native people in Minneapolis were being arrested by the busloads, you know, a police paddy wagon would pull up to the back of back of a bar, and at the front of the bar the police would come in… and so people would start leaving out the back and the paddy wagon would be right there, and they would just load people up.

"Police brutality was at its worst in the late '60s against Native people. And that was when people like my father Dennis Banks, Clyde Bellecourt, Vernon Bellecourt, and other leaders came together and formed the American Indian Movement. It started out as a community-organised group that were trying to protect each other, and look out for one another. And then it just grew very quickly from there."

AIM came to national prominence in 1973 when it established a foothold in the village of Wounded Knee on the Pine Ridge reservation, leading to a 71-day standoff with federal agents.

Mr Peltier's attorney Kevin Sharp, a former federal judge, said the FBI created a "powder keg" environment through its tactics against AIM.

On June 26, 1975, agents entered Pine Ridge to serve arrest warrants, which sparked a confrontation.

According to a statement from current FBI director Christopher Wray, agents Jack Coler and Ronald Williams were shot in the head at close range after being injured in a shootout.

AIM member Joseph Stuntz was also killed, shot by a law enforcement sniper.

While two other AIM members, Robert Robideau and Dino Butler, were acquitted of killing agents Coler and Williams, Mr Peltier was ultimately convicted of two counts of murder after being extradited from Canada, and sentenced in 1977 to life in prison, despite defence arguments that evidence against him had been falsified.

The trial was characterised by frequent misconduct by the prosecution, and his imprisonment has drawn condemnation from prominent human rights leaders, including Pope Francis and Nelson Mandela.

Many US members of Congress, including senators, have urged his release, and Amnesty International has run a long-term campaign on his case.

Senator Brian Schatz (D-Hawaii), chair of the Senate Committee on Indian Affairs and a Native American man, told the Huffington Post: "Leonard Peltier has been imprisoned for nearly 50 years, and now suffers from severe health issues... It's time for him to go home and live out his remaining days with his family and his community."

There was never any material evidence Mr Peltier killed the two agents, but after the deaths of Mr Stuntz and the acquittal of Robideau and Butler, he was the prosecution's target.

There were dozens of people present at the shootout. Mr Peltier was separated from his co-defendants, all of whom were acquitted on grounds of self-defense, and prosecutors with-held evidence during the trial.

It has been alleged the FBI threatened and coerced witnesses, and a juror who admitted on day two of the trial that she was prejudiced against Native Americans was kept on the jury.

At a 2009 parole hearing, his last, Mr Peltier was effectively offered release if he said he had killed the FBI agents, but he refused and parole was denied.

His attorney, Mr Sharp, told Huffington Post: "You've got a conviction that was riddled with misconduct by the prosecutors, the U.S. Attorney's office, by the FBI who investigated this case and, frankly the jury... If they tried this today, he does not get convicted."

The parole hearing was held in secret at the Federal Correctional Complex Coleman in Florida, without public or media presence, and no details have been released about proceedings to date.

A decision based on the hearing is due within 21 days, and must be delivered on 1 July at the latest.