In the 1990s, Harold and Dewayne Damper were involved in a drug trafficking operation that brought cocaine from Southern California to Jefferson Davis County, Miss. — at the rate of about one kilo of cocaine a month, prosecutors said.

The two brothers, known as "Odie" and "Doogie," were indicted together, tried together, given the same sentence and, until recently, served their sentences at the same minimum-security prison.

And when President Obama announced a clemency initiative to give drug dealers like them a second chance, both applied for presidential clemency.

Dewayne received a commutation and was released to a halfway house last week. Harold's case was denied. He's still in prison.

The Damper case illustrates a central challenge in the clemency initiative, as the Justice Department has tried to evaluate the record 32,551 commutation petitions it's received during the Obama presidency. Each case is reviewed separately and on its own merits, leading to complaints that the criteria are often applied inconsistently and subjectively.

"I've looked at a lot of cases and wondered, why this guy and not that guy? It's the process. When you have a process that is vertical and goes through seven layers of review, you’re going to get aberrational results," said Mark Osler, a law professor at the University of St. Thomas in Minnesota and a leading advocate of reforming the clemency system. "The problem is the process, not the president."

Those layers of review include staff attorneys and the heads of the Office of the Pardon Attorney, the Deputy Attorney General's Office and the White House Counsel's Office. Only then do the recommendations go to the president. The constitution gives the president alone the power to "grant pardons and reprieves for offenses against the United States." Commutations are a lesser form of pardon that releases convicted criminals from prison but otherwise leaves the conviction intact.

Neither the White House nor the Justice Department would comment on the Damper case. But the brothers appear to have been treated differently even before their petitions were filed.

Both sought the help of the Clemency Project 2014, an independent coalition of defense attorneys that agreed to take on clemency initiative cases for free. Dewayne received a free attorney. Harold did not, and filed his petition himself.

"I didn't get no feedback from them or nothing. I didn’t get looked at, really," Harold said in an interview from the low-security prison in Lompoc, Calif. "To me, it's the luck of the draw who gets a lawyer. That's all it is."

Osler said the clemency process has inadvertently perpetuated the injustices in the criminal justice system. "If you have a good lawyer, you're most likely to get a shorter sentence in the first place. And now with clemency, if you have a good lawyer for that, that helps you, too."

The Clemency Project would not discuss individual cases. But Project Manager Cynthia Roseberry said each case is reviewed on its own merits.

"I will say this generally. Not only during this project, but in my 20 years of practice, I've never found two identical defendants. Not even in the same case," said Roseberry, a former federal public defender. "Each defendant has their own privacy issues and their own particular circumstances, regardless of being related to each other or not. So the lawyers would have looked at them independently."