Ronald Smith's clemency application says he is a changed man who suffered through an abusive childhood.
Smith's lawyers filed the necessary papers Wednesday with the Montana Board of Pardons and Parole in Deer Lodge, Mont.
Smith, 54, has exhausted all other appeals.
"In the face of the harsh circumstances of being locked down in virtual isolation for 28 years, he has nonetheless made a genuine attempt to live a life that exhibits remorse, rehabilitation, a changed heart and mind and a potential for good," reads the document prepared by lawyers Greg Jackson and Don Vernay.
"We request that you consider and grant this application and commute Mr. Smith’s sentence from death to life without parole."
The application is supported by a letter from the Canadian government.
"The government of Canada does not sympathize with violent crime and this letter should not be construed as reflecting a judgment on Mr. Smith's conduct," says the Dec. 5 letter from Foreign Affairs Minister John Baird.
"The government of Canada ... requests that you grant clemency to Mr. Smith on humanitarian grounds."
Stephen Harper's government initially balked at supporting Smith's bid, saying he had been convicted in a democratic country. But the Federal Court forced the government to act on Smith's behalf.
Smith, originally from Red Deer, Alta., pleaded guilty to two charges of deliberate homicide and two charges of aggravated kidnapping in February 1983 and requested the death penalty. He rejected a plea deal offered by prosecutors which would have given him life in prison.
He later changed his mind and asked the District Court to reconsider the death penalty. That led to three decades of legal wrangling.
Smith was 24 and taking LSD and drinking when he and two friends met up with Thomas Running Rabbit and Harvey Mad Man Jr. near East Glacier, Mont. Smith and Rodney Munro marched the two men into the woods where Munro stabbed one of the victims and Smith shot both of them.
Munro accepted a plea deal, was eventually transferred to a Canadian prison and has completed his sentence.
Smith’s lawyers say his drug and alcohol use impaired his judgment. They also say he received poor advice from his lawyer at the time.
"As a result of the combination of his guilt over the offences, his virtual isolation in a foreign country without consular assistance, and the deplorable actions of his trial attorney, he instead chose to plead guilty and requested the death penalty," argue Jackson and Vernay.
"Upon being placed in a less isolated environment, he immediately realized both the foolishness and impulsiveness of his actions and sought ... the original sentence offered by the state of Montana, but the state has adamantly refused to consider his request."
The document says Smith began drinking as early as age 11 and was the eldest of four children who grew up in a violent and dysfunctional household. His father, an oilfield worker, was gone for long periods of time, which left Smith as the de facto man of the house. When his father would return, the violence would continue.
"Dolores Smith (mother) relates entering the room after Ron was abused by his father and seeing blood spatters on the walls from the beating Ron suffered at the hands of his father," says the application.
"Ron’s sisters kept their suitcases packed, underneath their beds. They both relate that Ron was their 'protector and confidant.'"
Smith's lawyers also note that he had no prior history of violence before his arrest in Montana, has expressed remorse and accepted responsibility.
The board of pardons and parole is likely to schedule a hearing on the application sometime this spring. It will make a recommendation either for or against clemency, but the ultimate decision will fall into the hands of Montana Gov. Brian Schweitzer.
Jackson told The Canadian Press he is "cautiously optimistic" about the application, but said it is a tough case.
After representing Smith for decades he admits it is sobering to realize it is coming to an end.
"As we were finalizing this and filing it, the realization really came home to us that after all these years, appeals are exhausted and this is virtually the last step," said Jackson in a telephone interview from his office in Helena, Mont.
Smith, who has reconnected with his family, including a daughter, just wants it to be over, said Jackson.
"He wants a resolution. He has obviously lived with the uncertainty of this for essentially 30 years."