(CNN) They met for the first time a few weeks before Christmas -- the woman serving a life sentence for killing a man who bought her for sex as a teenager, and a pastor who believed in her.

At the time of their meeting, high-profile advocates had been calling for clemency for Cyntoia Denise Brown , including a US Congressman and A-list celebrities like Ashley Judd . Gov. Bill Haslam had heard from both sides on whether to grant her clemency.

Members of Bishop Joseph W. Walker III's congregation were working with Brown through a Tennessee Department of Correction faith-based mentoring program

Days after meeting her, Walker joined the chorus of people lobbying the Republican governor. He spoke to Haslam about forgiveness and second chances, Walker said.

On Monday, as one of his final acts in office, Haslam granted the 30-year-old Brown clemency after she served 15 years in prison. She will be released to parole supervision on August 7, according to the governor.

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"We're here today because a moral man made a moral decision, a courageous decision," Walker said. "We're here today because this was not just an act of one intervention by myself but the cumulative effort of many around the country, around the world, who prayed, who advocated, who tweeted, who talked about it."

In 2004, Brown killed Johnny Mitchell Allen. The then 16-year-old said he had solicited her for sex and taken her back to his house. Prosecutors said Brown shot Allen in the head while he was asleep and stole his money and guns, took his truck and fled the scene.

Prosecutors argued that it wasn't a killing in self defense, but a robbery.

Brown had said she was scared for her life by Allen's behavior and took the money because she was afraid of returning empty-handed to her pimp, nicknamed "Cut Throat." A juvenile court found her competent to be tried as an adult. She was convicted of murder and robbery in 2006 and given the life sentence.

I encourage and plead with my Tennessee Governor @BillHaslam to grant #Clemency4Cyntoia. Cyntoia Brown was a victim of child sex trafficking, raped and forced into paid sexual exploitation to stay alive. She deserves our empathy and your mercy. — ashley judd (@AshleyJudd) December 17, 2018

Since that conviction, juvenile sentencing guidelines in Tennessee have been amended.

Brown has spent all her adult life in prison, but her advocates say she has worked to transform herself during her time behind bars. She received her associate's degree from Lipscomb University in 2015 and is expected to complete her bachelor's degree in 2019, Haslam's office said

'This incredible angel'

Walker, the pastor at Mount Zion Baptist Church, said he believed Brown deserved clemency before they met. He wanted to talk to her first before talking to Haslam, he said.

He met Brown that day in December as she wrapped gifts from inmates for children in the community.

She already knew members of Mount Zion's ministry and had watched Walker preach on television. She wanted to get involved in Mount Zion, Walker recalled.

"This incredible angel, full of compassion, full of selflessness, full of love began to open up just about how she wanted to just make a difference, how she was positive, and how nothing was going to break her."

Walker said he saw "how giving she was, how transformed she was and focused on her future and helping other people."

They fist-bumped, and he pledged to talk to Haslam on her behalf, he said.

"Next time I see you, I'm going to be walking you out of here," he recalled saying.

Ed Yarbrough, a Nashville attorney on Brown's legal team, said many people lobbied for Brown's release. Two members of the legal team met with Haslam twice in person to state Brown's case, including one meeting that lasted more than an hour.

He said they also encouraged clergy and state lawmakers, and "anybody that we thought would have a strong enough voice and enough credibility" to talk to Haslam.

'She's paid her debt to society'

In a roughly hour long phone conversation during the week before Christmas, Walker said Haslam was conflicted about what to do.

The pastor said he helped Haslam "understand the broader issue of forgiveness and second chances."

"Consequences don't always have to be terminal. Consequences could happen, but they could have term limits," he said.

Walker said he framed the issue as an opportunity for reconciliation, "not just for Cyntoia, but for government, for policing, for communities."

"I said 'it's not like we're asking for clemency for somebody who's been in jail for six months,' " he said. "She's paid her debt to society. ... The moral issue is, does this rise to the level of forgiveness and a second chance based upon what she has done?"

In an email, Lindsay Bales, a spokeswoman for the governor, said "Governor Haslam did speak with Bishop Walker, who he has had a relationship with for several years, in addition to several other individuals." She declined to give details about that conversation.

The governor in a statement on Monday said Brown "committed, by her own admission, a horrific crime at the age of 16."

"Yet imposing a life sentence on a juvenile that would require her to serve at least 51 years before even being eligible for parole consideration is too harsh, especially in light of the extraordinary steps Ms. Brown has taken to rebuild her life," Haslam said. "Transformation should be accompanied by hope."

In August, Walker said he will "walk her out, hold her hand."

"I think it'll be a day that will awaken something in all of us, about hope. About when the odds are stacked against you like that, to never lose hope," Walker said.