(ABC News) -- After she was gravely wounded by gunfire two years ago in Tucson, Ariz., former Rep. Gabrielle Giffords and her husband, Mark Kelly, imagined a life out of the public eye, where she would continue therapy surrounded by the friends, family and the Arizona desert she loves so much.
But after the slaughter of 20 first-graders and six adults at Sandy Hook Elementary School in Newtown, Conn., last month, Giffords and Kelly knew they couldn't stay silent.
"Enough," Giffords said.
The couple marked the second anniversary of the Tucson shooting by sitting down with Diane Sawyer to discuss their recent visit to Newtown and their new initiative to curb gun violence, "Americans for Responsible Solutions."
"After the shooting in Tucson, there was talk about addressing some of these issues, [and] again after [a movie theater massacre in] Aurora," Colo., Kelly said. "I'm hopeful that this time is different, and I think it is. Twenty first-graders' being murdered in their classrooms is a very personal thing for everybody."
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During their trip to Newtown, Giffords and Kelly met with families directly affected by the tragedy.
"[The] first couple that we spoke to, the dad took out his cell phone and showed us a picture of his daughter and I just about lost it, just by looking at the picture," Kelly said. "It was just very tough and it brought back a lot of memories about what that was like for us some two years ago."
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"Strength," Giffords said she told the families in Newtown.
"Gabby often told them, 'You got to have strength. You got to fight for something,'" Kelly said.
The innocent faces of the children whose lives were abruptly taken reminded the couple, they said, of 9-year-old Christina-Taylor Green, the youngest victim to die in the Tucson shooting at a Giffords constituent event.
"I think we all need to try to do something about [gun violence]," Kelly said. "It's obvious to everybody we have a problem. And problems can be solved."
Giffords, Kelly Call for 'Common Sense' Solutions
Giffords, 42, and Kelly, 48, are both gun owners and supporters of the 2nd Amendment, but Kelly had strong words for the National Rifle Association after the group suggested the only way to stop gun violence is to have a "good guy with a gun."
There was a good guy with a gun, Kelly said, the day Jared Loughner shot Giffords and 18 other people, six fatally, at her "Congress on Your Corner" event.
"[A man came out] of the store next door and nearly shot the man who took down Jared Loughner," Kelly said. "The one who eventually wrestled [Loughner] to the ground was almost killed himself by a good guy with a gun, so I don't really buy that argument."
Instead, Giffords and Kelly are proposing "common sense" changes through "Americans for Responsible Solutions."
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The first change the couple hopes to enact is to require a comprehensive background check for the private sale of firearms.
"I bought a gun at Walmart recently and I went through a background check. It's not a difficult thing to do," Kelly said. "Why can't we just do that and make it more difficult for criminals and the mentally ill to get guns?"
The debate over high-capacity magazines and assault weapons has been renewed after the Sandy Hook Elementary School massacre.
Kelly, a veteran of Desert Storm and a gun owner, said he doesn't believe an extended magazine is necessary for the sport.
"An extended magazine is used to kill people," he said, "lots of people."
Loughner used a magazine that had 33 rounds in Tucson, while accused Aurora shooter James Holmes had a 100-round magazine. Adam Lanza, the Newtown shooter, used numerous 30-round magazines to load his Bushmaster AR-15.
Finally, Kelly hopes to address the issue of how the mentally ill are treated in the United States. Loughner, who was deemed incompetent to stand trial, pleaded guilty to 19 counts in August.
"Jared Loughner was clearly mentally ill," Kelly said.
"Sad," Giffords added.
Kelly said, "We have to learn how to identify these people and get them treatment. And we don't do a very good job at that."
At Loughner's sentencing in November, Giffords, unwavering, looked him straight in the eyes. It was the first time she and Kelly had seen Loughner in person.
"Daggers," Giffords said.
"Yeah, Gabby was staring daggers into his eyes," Kelly said.
Loughner stared back.
"He's highly medicated and the medication apparently makes him a little bit more rational, where he can understand things, but he's clearly mentally ill," Kelly said. "We wanted to make sure that he heard directly from us about the effect that what he did had on Gabby and the community."
Kelly delivered a statement, speaking to Loughner directly about the day that forever changed their lives: Jan. 8, 2011.
"Mr. Loughner, you may have put a bullet through her head, but you haven't put a dent in her spirit and her commitment to make the world a better place," Kelly said at the Nov. 8 sentencing.
"You have decades upon decades to contemplate what you did. But after today, after this moment, here and now, Gabby and I are done thinking about you."
Loughner was sentenced to seven consecutive life terms plus 140 years in prison without parole.
Giffords Recovery a 'Struggle'
Two years ago, doctors were unsure if Giffords would survive a gunshot wound to her head or what her prognosis would be.
She's made a remarkable recovery since then, but still has a long way to go.
"Physical therapy, yoga, speech therapy," she said.
Recovery is frustrating at times for the outgoing Giffords.
"She complains that her improvement is slow," Kelly said.
"But you're working hard," he said to his wife.
Giffords has a new companion, a service-dog named Nelson.
The former congresswoman, who loved being active outdoors before the shootings, has been able to slowly ease back into some of her favorite activities.
She's been able to ride a horse and hopes to take a bike ride soon with Kelly on a tandem bike he is getting modified.
This is not the life Giffords imagined, but her fighting spirit has been an inspiration for many. She plans to apply that same resolve in her mission to end gun violence, Kelly said.
"Gabby works very hard in her rehab," Kelly said. "Now we intend to work very hard on this new project." hope that this kind of thing doesn't happen again. And you know what? It does happen again."