This is the final part of a three-part series that takes a look at the case of Clarence Aaron, a one-time college student whose involvement in a 1993 cocaine deal got him three life sentences in federal prison.

Click here to read Part One.

Click here to read Part Two.

Clarence Aaron's road has been long.

Sentenced to three concurrent life terms in prison for introducing two drug dealers in 1993, he has spent the last 15 years in high-security federal prison. He is 39 years old and he will spend the rest of his life in prison — unless the president of the United States commutes his sentence.

A junior at Southern University in Baton Rouge, La., Aaron was convicted of conspiracy to distribute 24 kilos of crack cocaine in 1993. He refused to plead guilty and to testify against his co-conspirators. His partners, career drug dealers, flipped on him and testified against him at his trial.

Mandatory minimum sentencing guidelines on crack charges were harsh, and he was sentenced to three terms of life in prison. In 1996, a court denied his appeal.

Aaron tried to get the federal court to re-sentence him this year based on changes to the drug laws in 2007 that made some sentences less harsh, but the judge ruled there was nothing that could be done.

The amount of drugs involved was just too great, and the changes in the law didn't apply to Aaron, even if the result seemed unfair.

His legal avenues are exhausted. Now his only hope of ever walking out of the federal prison in Coleman, Fla., is a grant of clemency from the president.

Aaron has had an application in with the Justice Department's Office of the Pardon Attorney since 2001. The office reviews clemency applications — for pardons and sentence commutations of federal convicts — and makes recommendations to the president.

The Justice Department does not comment on pending cases. But Aaron's chances don't look good.

During his time in office, President Bush has received almost 8,000 petitions for commutation from federal convicts.

He has granted eight.

One was his friend and Vice President Dick Cheney's aide, Lewis "Scooter" Libby, who was convicted of obstruction of justice, perjury and making false statements concerning the outing of CIA agent Valerie Plame Wilson. The Pardon Attorney's office said Libby did not apply.

Bush commuted the sentences of non-violent drug offenders John Edward Forte of North Brunswick, N.J., and James Russell Harris of Detroit in November in his first round of clemency actions since March.

The other five whose sentences were commuted were also jailed for drug-related crimes.

Bush has used his power to grant reprieves and pardons less frequently than his predecessors in the White House. Former President Bill Clinton commuted the sentences of 61 federal convicts and pardoned 396.

One of the felons on Clinton's list was Dorothy Gaines, who, like Aaron, was convicted on drug conspiracy charges. She was released on Dec. 22, 2000, and now does public speaking engagements on mandatory minimum sentencing laws.

In addition to his eight sentence commutations, Bush has pardoned 157 convicts, including 14 last month.

Bush is expected to make additional decisions on pardons and sentence commutations before he leaves office in January. Decisions on petitions that aren't reviewed and decided upon before the transfer of power will be made by the Obama administration.

"Clarence Aaron's life without parole sentence is exactly the sort of abusive punishment [that] the presidential pardon was designed to redress," said Debra Saunders, a columnist for the San Francisco Chronicle who has been writing about Aaron's case in her column for several years.

"When the feds put away drug kingpins for long terms, the system works. But when they free two kingpins and put a nonviolent low-level novice behind bars for the rest of his young life, I believe President Bush's sense of justice and compassion will compel him to free Clarence Aaron," she said.

Eric Sterling, former counsel for the House Committee on Judicial Affairs and president of the Criminal Justice Policy Foundation, said that drug offenders deserve punishment, but agrees that in the case of Clarence Aaron, the president would be right to commute Aaron's sentence.

"He's been in 15 years. Before the mandatory minimums were enacted, the maximum you could get under the federal controlled substances act was 15 years unless you were convicted of the kingpin statute ....

"He has served enough time. Justice is done."

Aaron wrote in a declaration to the court this year when he sought a resentencing that he regrets his decision to participate in the drug deal, and that he has accepted responsibility for his actions.

"Every day I wake up I have to deal with my reality. Those years ago, I made a horribly selfish, foolish and wrong decision that I am truly sorry for. I so regret all the hurt and damage I have caused others through my transgression," Aaron wrote.

"One of my life goals is to be the best person I can be. I want to be the best son, uncle, friend and citizen I can be. As I sit here now and reflect on my current plight, I feel the growth, maturity and strength that my experience in prison has, in God's loving hands, brought about in me. I just pray for a second chance to be a productive citizen."