PINELLAS COUNTY, Fla. — Robby Mast met Lindsay Haugen in August of 2015, and within one month the Pinellas County native would be dead at her hands.

Some call Haugen a cold-blooded killer.

Robby’s mother Dori Greeson and his stepfather, Gene Greeson chose to forgive Lindsay.

It’s a story that gained national attention on the Netflix show, "I Am a Killer."

Letters to Lindsay — that’s how the Greesons connect with Robby’s killer, granting her forgiveness.

"I had no idea it would go this far," Dori said.

"They cared enough about me to let me know how to escape hell,” Haugen said. “How to live a better life for God."

The relationship between the parents and prisoner grew beyond pen and paper.

The Greesons went to Montana in 2017 to visit Lindsay in prison.

That first visit lasted eight hours and now they go every summer.

They sing, pray, and bond.

“Dori is, I think, my best friend, outside of God, of course," Haugen said.

“I often tell people we lost a son but we gained a daughter,” Gene expressed.

The bond grows between prison visits, along with video chats three times a week.

An unexpected relationship Dori said. "I do consider her a very dear friend."

A flourishing friendship, one that has raised a lot of questions about the love, laughter, and friendship the couple shares with the woman who murdered their son. A relationship unsettling for some.

"It does upset me when someone says I didn’t love him," said Dori.

Spectrum Bay News Nine’s Melissa Eichman asked Gene and Dori how they respond to people who can’t quite comprehend the relationship.

"Jesus doesn’t leave me,” said Dori. "I’m so confident that He paid the price for the world’s sin, all of our sins, and it just includes Lindsay’s, it includes the murder, so yeah, so I forgive it, I forgive that sin. It doesn’t mean I excuse it, not at all." Dori went on to say, “She should’ve helped him and I believe that with all my heart that she should’ve helped him. She did not do what she was supposed to do and she certainly knows that.”

Gene and Dori are confident they’re doing exactly what they’re supposed to do.

“Jesus died to pay for our sins and offers us forgiveness as a gift if we will simply believe Him for it,” said Gene. “Many people when they let their bitterness go and that’s what happens when you truly forgive, then it just makes them overjoyed.”

Some aren’t convinced Lindsay is sincere. 

“She’ll tell you that she took Robby’s life out of kind of like a mercy killing, he asked for her to kill him,” said Detective Hallam, who investigated the September 2015 case in Billings, Montana. “I don’t believe that one bit.” 

“Lindsay overheard this conversation and basically he was telling his friends, I’m basically using Lindsay just as a ride to get me back over to Minnesota so I can see my girl,” said Detective Hallam. “It sounds like Lindsay didn’t take very kind to that, obviously hearing those words she probably felt used.”

The detective questions if Lindsay is manipulating the Greeson’s to potentially benefit her later, possibly at a parole hearing.

"It’s just not the case, their relationship means the world to me,” said Haugen. “But if I have to serve my entire term and I’m here until I’m 96-years-old, that’s fine.”  

Lindsay is eligible for parole in 2030.

Her former prison chaplain Pastor Grove Hull said she is flourishing in forgiveness.

"She has this freedom in her spirit because Jesus has set her free from what she has done," said Pastor Hull. "She had a joy and a purpose in life that most of the inmates didn’t have.”

"I can live my life knowing that I’m forgiven and I can make a difference in someone else’s life by way of hope," said Haugen who says she is now active in spreading God’s word to other inmates.

Gene and Dori’s hope is people can learn to forgive others too.

"Forgiving her and having this relationship with her and loving her, I am confident that that’s the right thing to do,” said Dori. “And I think I’m receiving more joy and more peace and more release than I would otherwise."

While Dori and Gene remember Robby’s life, the couple moves forward choosing to forgive his death.

Not all relatives and friends agree with the Greesons, saying Robby’s killer should not have a voice and they wish to mourn and remember Robby privately.

“What people think of us matters very little, what they do with this subject matters a whole lot,” Gene says of forgiveness.

The couple says coverage has raised a lot of questions, so they posted a video in hopes of answering them.