Erik Menendez's Wife Reveals Why She Decided to Marry Convicted Murderer (Exclusive)

Both brothers tied the knot after being locked up. Lyle was married to Anna Eriksson from 1996 to 2001, before saying "I do" with Rebecca Sneed in 2003, while Erik exchanged vows with Tammi Saccoman in 1999.

In TooFab's exclusive sneak peek at Thursday's final episode of A&E's documentary series "The Menendez Murders: Erik Tells All," Tammi gives some insight into their unique relationship.

"The reason why I decided to marry him was I had no rights as just being somebody that knew him," she says. "Not that I wasn't emotionally attached, I was, but I really had a main concern about his welfare and what they were gonna do and a wife has more say about what can be done and what they can do to him."

"I was in love with him, I still am in love with Erik," she continues. "I know that he's got issues and he's been damaged from what his parents have done to him, but in his heart and soul I know he's a good person and I think that for the rest of my life I will be his best friend."

The two struck up a relationship after she wrote him a letter expressing her support for him during the trial. After the trial and retrial ended and he was convicted of first-degree murder, Erik credited Tammi with keeping him sane.

"There was a tremendous amount of suffering that goes through when you go through those prison doors and you live in that world, you're going to suffer," he explains. "For me, my marriage to Tammi was the most critical part of being able to endure. My love for Tammi is eternal."

He also praises her "incredible sacrifices" and decision to allow him into her daughter's life as well, something which allows him to "experience what it's like to be a father."

"Tammi's given me the love and that spiritual purpose that I've found in life has given me meaning," he adds, "those are the things that have gotten me through."

The season finale of "The Menendez Murders: Erik Tells All" airs Thursday night on A&E.