Ronald Smith, the only Canadian on death row in the United States, pleaded with Prime Minister Stephen Harper on Wednesday to consider "who I've become" and not "who I used to be" in supporting the cause of clemency for the Alberta-born killer, who could face death by lethal injection later this year for murdering two young Montana men in 1982.

In a wide-ranging telephone interview from Montana State Prison, conducted just weeks ahead of a two-day clemency hearing in early May that could determine the 54-year-old convict's fate, Smith told Postmedia News that "the level of maturity I've gained over the last 15 or 20 years, I think, is a huge difference."

But he acknowledged — surprisingly — that he could see himself supporting capital punishment in certain situations for particularly heinous criminals, such as British Columbia serial killer Robert Pickton.

"Sometimes," Smith said, "you gotta put the mad dog down."

In his own case, however, the Canadian inmate expressed disappointment with a recent letter from the federal government in which Foreign Affairs Minister John Baird appeared to offer only lukewarm support for Smith's formal clemency application, submitted last month to Montana's parole board.

"Obviously, they said that they were backing the petition, but just the substance of the letter — they left little doubt that they were being forced to do it. So it's a little bit difficult to say they're backing me," said Smith, echoing concerns expressed by opposition critics that the federal Conservative government has little genuine interest in convincing Montana Gov. Brian Schweitzer to commute Smith's death sentence.

In the letter, Baird prefaced his official expression of support for clemency by noting that the government was ordered by the Federal Court of Canada to back Smith. Baird then stated that the government "does not sympathize with violent crime" and that Canada's formal request for clemency "should not be construed as reflecting a judgment on Smith's conduct."

Montana's justice department issued a statement on Wednesday saying it will push forward with plans to execute Smith.

"The state of Montana will file a written response opposing Ronald Allen Smith's petition," said department spokesman John Doran, "and intends to defend the strong court record upholding his original death sentences."

Smith's case has resonated loudly in national politics since October 2007, when the Conservative government abruptly halted all diplomatic efforts to win clemency for the condemned Canadian.

At the time, Harper said Canada would take a "case-by-case" approach to clemency cases but that working to prevent the execution of a "double-murderer" like Smith would amount to sending "the wrong signal" to Canadian citizens from a government intent on "tackling violent crime."

Two years later, though, a lawsuit prompted by the new Conservative policy led a Federal Court judge to declare the reversal "unlawful" and to order Canadian officials to relaunch the lobbying effort to save Smith's life — a ruling the government chose not to appeal.

Harper and Baird "are obviously looking at who I used to be," Smith said in the interview. "You know, if they're going to look at the overall picture, then look at what I've done and who I've become. It's all well and good if you want to look at one aspect of my life. But I'm a more full, complete person than what I used to be."

Smith's 19-page clemency request, accompanied by two lengthy letters of support from a Catholic priest and a retired prison educator, detailed his record as a model inmate, the abusive childhood Smith suffered growing up in Alberta and his "heartfelt remorse" over the killings — now almost 30 years ago — of Harvey Mad Man and Thomas Running Rabbit.

Although Smith confessed to those murders, he said too many people in the U.S. have been proven innocent after being executed, proof that "the death penalty doesn't work" in a world where judges and juries can make mistakes.

"If you're executing innocent people, it's murder," he added. "It doesn't matter what kind of a label you put on it. It's murder."

But, unexpectedly, the man who in recent years has become a lightning rod in renewed debates over capital punishment in Canada said he can imagine scenarios in which the execution of an exceedingly monstrous criminal is justified.

Asked whether he thinks it might be acceptable for the state to a carry out a death sentence for convicted serial killers such as Pickton — the B.C. pig farmer believed to have killed 49 women in the Vancouver area between 1983 and 2002 — Smith responded: "Yeah, I actually do. . . . Like this Pickton dude, if he's that horrible, it's hard to argue against it."

In August 1982, during a booze- and drug-fuelled hitchhiking trip to the U.S., Smith and two friends from Alberta were picked up in northern Montana by Blackfoot Indian cousins Mad Man, 20, and Running Rabbit, 24.

To steal their car, Smith dragged the two men into the woods and shot each in the back of the head.

After his arrest in Wyoming three weeks later, Smith initially confessed that he had committed the murders to see "what it was like" to kill another human being. He also asked a judge to impose a death sentence.

During a 2007 interview with Postmedia News, Smith said the claim that he killed Mad Man and Running Rabbit just to satisfy his curiosity about murdering people was invented to help ensure his initial, depression-fed death-wish would be granted.

"I had one thing and one thing only in mind, and that was to force the judge to give me a death sentence," Smith stated at that time.

Smith later changed his mind about wanting to be executed, and his lawyers have fought for more than 25 years — most of that time with the help of the Canadian government — to have the Albertan's death sentence commuted to a term of life imprisonment.

In Wednesday's interview, Smith said he wished he could apologize directly to the relatives of his victims. He also said that even if he is granted clemency, he doubts he would ever be transferred to a Canadian prison or be released from jail before the end of his life — a hope he was still harbouring at the time of the 2007 interview.

Finally, he expressed some sympathy for Schweitzer because of the life-or-death judgment he will likely have to render before the end of this year.

"I honestly wouldn't want to be in his shoes right now," said Smith. "You've got to stop and think: if he decides against me, he's ultimately sentencing me to die. It's not an easy decision to make."

rboswell@postmedia.com