Steven Avery and Lynn Hartman were engaged in early September after eight months of dating, she tells PEOPLE

How Making a Murderer's Steven Avery Fell in Love Behind Bars: New Fiancée Says, 'It Was Just Like Magic'

Lynn Hartman wanted nothing to do with Steven Avery.

The 53-year-old Las Vegas legal secretary was divorcing a 30-year-veteran law enforcement officer when her daughter, Kamilia, suggested she stop sulking and watch Making a Murderer – the Netflix series about Avery’s 2005 conviction for the murder of 25-year-old Wisconsin photographer Teresa Halbach.

Get push notifications with news, features and more.

“At first, I wasn’t interested because I was a Nancy Grace fan, and I believed what she said about the case,” Hartman tells PEOPLE. “So my answer to my daughter was, ‘I don’t want to watch it – I already know [Avery’s] guilty.’ ”

Eventually Hartman caved, coming around on his innocence – and him.

As she describes it to PEOPLE, what followed is an unlikely love story that led to the two getting engaged over the phone in the early hours of Sept. 6.

Watching the 10-part Netflix series, Hartman (like many, but not all) came to believe its suggestion that Avery had been framed in retaliation for filing a $36 million lawsuit against Manitowoc County, Wisconsin, and local authorities after a wrongful conviction for rape that sent him to prison for 18 years.

Feeling bad for Avery, 54, Hartman decided to write him a letter and send with a handful of pictures, offering him “any kind of support I could in any way that I could,” she says.

She didn’t expect a response. But when she got one, Hartman says she got to see the human side of Avery. And the more she got to know him through letters – and eventually phone calls – the more she realized, she says, that he was actually the one helping her.

‘That’s What I Fell in Love With’

“As it turned out, he became a support system for me,” Hartman tells PEOPLE. “My divorce was crushing – it almost killed me. Here I am talking to a man convicted of murder, and he was my support system. But that’s what I fell in love with. This man still had the love in his heart to reach out to people and write them with support.”

The two had a lot to talk about. “It was just a joy to get his phone calls,” Hartman says. “His letters aren’t necessarily grammatically correct and his spelling isn’t necessarily great, but when you got him on the phone – he’s a very intelligent individual.”

Despite the grim context for their chats, “in the beginning of our relationship, we spent a lot of time laughing,” Hartman says. “He’s a very happy – very loving, very selfless. He’s got a great support system with this family. He just wasn’t the monster Nancy Grace made him out to be.”

At the end of their first phone call, Avery told her he loved her.

Even though she was developing feelings for Avery, Hartman says she was still nervous to go down a romantic path with Avery – especially after just getting out of a relationship with someone on the other side of the law.

“I kept flipping back to, ‘My ex-husband is a police officer and now I’ve got this inmate telling me he loves me,’ ” she says. “So it was a conflict that I really went through in my mind. It was a different life for me.”

Their First Meeting

Despite concerns from friends and family, Hartman eventually felt comfortable enough to meet Avery in person. Although she says she was initially “scared to death” going alone – having never been inside a prison before – all of that changed when Avery walked in the room.

“It was just like magic,” Hartman says. “The first moment I laid eyes on him, I just thought he was a teddy bear. The chemistry was there. He came over and sat at the table and we held hands. And it was exactly like I imagined for the months leading up to it.”

She continues: “We talked about what we want to do when he gets out. What are the possibilities of our lives together? And do we keep going until it happens? He told me about how much I meant to him, and how much our love meant to him.” And that’s certainly what I needed at the time, after my divorce, and what he needed, too.”

She says they both cried – an emotional moment that she says was made up of “tears of happiness, tears of joy and tears of sorrow.”

RELATED VIDEO: Ryan Ferguson Gives an Update on Making a Murderers’ Steven Avery & Brendan Dassey

‘My Life Became a Living Hell’

Their relationship hasn’t been embraced by all. As the two got closer, Hartman says she became the victim of online bullies who dug up civil records about her divorce, restraining orders she had filed against ex-boyfriends and a bankruptcy filing. She says these records were sent to Avery as “evidence” she was using him for his fame and potential fortune.

“My life became a living hell,” Hartman tells PEOPLE, adding that the rumors made her “terrified” to meet Avery’s parents at first.

“Throughout this relationship, I’ve seen articles written about me and they weren’t good articles,” she says. “Some claimed I was gold-digger, that I didn’t have good intentions, that the family thought I was a spy for the police – on and on and on. And these people didn’t know if it was true or not.”

The Averys embrace her now, which is something Hartman is happy about. “They’ve been through hell and they don’t need somebody who’s out there for a cheap thrill, messing around with ill intentions,” she says.

One person who has always stood by her side? Her 24-year-old daughter, Kamilia. “She has been a cheerleader from the beginning,” Hartman says. “And each time I felt like it might be too much for me to continue forward, she reminded me to continue on. Steven really respects her and has a lot of love for her. Because if it wasn’t for my daughter, I wouldn’t be here talking with you today.”

Hopes for the Future

“It makes me feel proud to get to know that he’s got some happiness and joy,” Hartman says. “There’s obviously people out there that don’t believe he deserves it – the people that believe he’s guilty. But I do not believe he’s guilty. And I feel very honored that I’m able to provide him with some happiness.”

Avery has consistently maintained his innocence in the Halbach murder (while Halbach’s family has consistently slammed the Netflix docuseries as one-sided, decrying the lack of focus on Halbach, the victim).

Chicago lawyer Kathleen Zellner, who specializes in wrongful convictions, announced in January that her firm would assume Avery’s representation, along with Tricia Bushnell, the legal director of the Midwest Innocence Project.

His nephew, Brendan Dassey, was also convicted of Halbach’s murder. But his conviction was overturned in August. He’s scheduled to be released in prison in the next two months.

Avery has been engaged twice before and married once, to Lori Mathiesen. They divorced in 1988 and have four children together.

As for her future with Avery, Hartman is hopeful.