Nearly 25 years into a life sentence for cocaine trafficking, Teresa Griffin had come to expect that being called to the warden's office meant an update on the latest relative to pass since her incarceration at age 26.

But one day last month, far better news waited on the other end of a phone call from a Minneapolis attorney who helped file her petition for clemency.

"You're going home," said the attorney, JaneAnne Murray, before the two broke out in tears.

Griffin was one of 42 people whose federal sentences for nonviolent offenses were shortened June 3 by President Obama — a group that also included a 73-year-old Minnesota drug kingpin who had served more than 25 years.

Griffin's release marked the first victory for a recent clemency program at the University of Minnesota Law School. The program is led by Murray, a law professor who is on the steering committee set up to screen the 35,000 inmates who applied for shortened sentences after the Obama administration announced its clemency push in 2014.

Murray's program follows the example of the nation's first clemency clinic, formed by a federal prosecutor-turned-defense attorney at the University of St. Thomas in 2012. Both groups are part of a volunteer battalion of professors, attorneys and law students working to win relief for offenders who would have received far lighter sentences today.

But the volume of petitions and the bureaucratic layers that pock the path to clemency signal more work to be done in the president's final months in office.

"These are people totally forgotten by the world," Murray said.

Filling a need

Griffin left behind four children, including a 6-month-old, when she was sentenced to life without parole. According to the American Civil Liberties Union, Griffin served as a mule to transport drugs for an abusive boyfriend who masterminded a cocaine conspiracy. Being sentenced, Griffin told the ACLU, was "like witnessing my own death."

Griffin is now one of 348 inmates whose sentences Obama commuted, more than the past seven presidents combined.

"I am granting your application because you have demonstrated the potential to turn your life around," Obama wrote Griffin in a June 3 letter.

The U program grew from three students in spring 2015 to eight in the past academic year. Four more are participating this summer, said Murray.

The group shifted its focus to Minnesota cases this past year, with the spring semester students being the first in the program to visit their clients.

Ross Edwards, of Phoenix, met his two clients at the federal prison in Sandstone and worked with their families to compile letters addressing the effects of their sentences to be filed with their petitions. "Their lives, their stories make it feel like there's something on the line," Edwards said.

Mark Osler, an attorney and St. Thomas law professor, has advocated for clemency reform in the years since working as a federal prosecutor in Detroit. "I helped cause the problem," Osler said of once pursuing mandatory minimum sentences for nonviolent drug offenders.

Since opening the country's first clinic at St. Thomas in2011, Osler has tried to convince other law schools to create programs of their own. He also started a one-year pop-up clinic for pro-bono attorneys that is now nearing its end.

Osler's law school program enlists six students for a full year, making prison visits a requirement.

"If you're going to tell someone's story, you're going to have to get to know who they are," Osler said. "There's no substitute to sitting down with them."

'Good luck and Godspeed'

The Clemency Project 2014 — on whose steering committee Murray serves — was formed to better help rewind the sentences for low-level offenders likely to have received lighter prison sentences under today's guidelines — particularly those who have served at least 10 years for nonviolent offenses.

Murray and Osler's students draft summaries of their cases that, if approved by Clemency Project committees, are returned to them to be drafted as petitions to send to the U.S. Pardon attorney. That kicks off a process in which the petition wends its way through seven layers of governmental review.

Osler has criticized the process as unduly burdensome but said law school efforts around the country to take on clemency cases have still created "net positives."

"You're obviously not going to solve the problem of there not being enough lawyers. It's not possible," Osler said. "But we have a large number of people coming out of St. Thomas, Yale, Harvard and the U of M focusing on this issue who are going to be advocates."

Even for Murray, a private defense attorney, visiting five women a decade into their prison sentences in Waseca was new. "That was the ­hardest day in my life."

Her students so far have included intellectual property specialists and a student now interning at the U.S. attorney's office in Minneapolis.

"Being able to attach a person to all those numbers and factors certainly helped," said intern Lindsey Lancette.

If fortunate, her client and others will receive a letter like Griffin now has, signed and stamped by the president. "I believe in your ability to prove the doubters wrong, and change your life for the better," President Obama wrote. "So good luck, and Godspeed."

Twitter: @smontemayor