"I don't. It certainly didn't cause this," Kelly said. "It didn't cause Jared Loughner to, you know, to plan this attack. ... I think you have somebody that's really, really disturbed, possibly schizophrenic."
Capt. Kelly admitted to Sawyer that he had been worried about his wife's safety in the past and that the two of them had discussed the death threats Giffords had received. "She's had death threats," he said. "As a lot of members of Congress have death threats. She's had them before."
Giffords has shared her own fears with her husband, telling him, "Someday, I'm really worried that somebody's going to come up to me at one of these events with a gun."
It was not an everyday fear but it was something that Giffords and Kelly took seriously enough to discuss a handful of times, he said.
When asked if he would ever be willing to meet with Loughner's parents, Kelly told Sawyer that he was open to the idea.
"I'd probably see them," he said. "I don't think it's their fault. It's not the parents' fault. I'd like to think I'm a person that's somewhat forgiving. And, I mean, they've got to be hurting in this situation as much as anybody.
Kelly said that when Giffords does begin to speak, they have plenty to talk about. One of the "hardest things," he said, will be having to tell her about the six people who died in the attack, including one of her dedicated staffers, Gabe Zimmerman, and 9-year-old Christina-Taylor Green.
"I was at her funeral the other day," Kelly said. "For a 9-year-old girl to die, you know, just because she was interested in democracy? I mean, it's just not fair."
In the hospital's ICU, Kelly has also comforted Susan Heilman, the woman who brought Green to the supermarket and was also injured in the attack. He said Heilman spoke to Green seconds before the shoo0ting began.
"She leaned down next to her and said, 'You know, someday, you know, you could grow up and be like Gabrielle Giffords.' And those were the last words she heard," Kelly said. "I mean, you just can't explain it."
Capt. Kelly is also facing the question of his own future; whether he will be the commander of the final space shuttle mission April 19, known as STS-134.
His crew sent a supportive tweet this weekend, saying, "Gabby is improving. Mark is strong ... STS134 will succeed."
Whatever the final decision, Kelly's heart will be right there with his wife.
Inside his wife's wedding ring, he had a message inscribed -- "You're the closest to heaven that I've ever been."
Giffords and Kelly will also have to decide whether she'll resume her work.
Sawyer asked, "Do you want her to go back into Congress after this?"
"That's a tough, tough decision. Probably not," Kelly said. "But I know that's probably not going to matter to her. I think she's such a devoted public servant that she's going to come out of this and be more resolved to fix things, to make things better for people."
Kelly has made sure to keep track of every gift, every message, every act of generosity from the people of Tucson, knowing that his wife will want to handwrite thank you letters.
"You know, she has Tombstone, Arizona in her district ... the town that's too tough to die," Kelly told Sawyer. "Gabrielle Giffords is too tough to let this beat her."