Rep. Gabrielle Giffords was only a few minutes into her “Congress on your Corner” meeting with constituents when the gunman struck. Now, one of her last acts in Congress will be to finish that meeting.

The Arizona Democrat announced Sunday that she will resign from her congressional seat this week, about one year after sustaining massive injuries in the massacre in Tucson that killed six, wounded 13 and sparked a nationwide conversation about the tenor of the country’s political debate.

She nearly died from the gunshot wound to her head, and the severity of the damage to her brain left the extent of her recovery in question. But it was in a clear and strong voice that betrayed only a hint of her ordeal that Giffords announced her decision, in a video posted on her campaign Web site.

“I don’t remember much from that horrible day, but I will never forget the trust you placed in me to be your voice,” she said, looking directly into the camera. The hair that had been severely cropped after the shooting now framed her face in soft curls. “I have more work to do on my recovery, so to do what is best for Arizona, I will step down this week.”

One last hurrah

Before handing in her resignation to House Speaker John A. Boehner (R-Ohio) and Arizona Gov. Jan Brewer (R), Giffords has some unfinished business. She plans to attend President Obama’s State of the Union address on Tuesday. And she will finish the meeting that was “interrupted,” her staff said in a statement, by gathering with some of the survivors at a private event in Tucson on Monday.

The announcement came as an emotional blow to many of her friends and supporters, who had hoped she would recover enough to run for reelection or even for the Senate. But it was not entirely unexpected.

For months, her devoted staff shouldered the burdens of her office while she underwent multiple surgeries and intensive therapy in Houston, where her husband, astronaut Mark Kelly, lived. Giffords made a remarkable recovery, but with her term ending this year, her constituents wondered whether she would be up to the challenge of running for reelection.

Bill Badger, a retired Army colonel who was injured in the shooting, said he does not begrudge her the decision.

“I fully support her decision to not run again and I understand, because I was shot in the head myself — not as seriously as Gabby — and I know how it changed my priorities and changed my life,” Badger said.

Giffords’s decision means that a special election will be held in the next few months, and despite rumors that her husband might run for her seat, Democratic officials in Washington and Arizona do not expect Kelly or any of Giffords’s top staff members to do so.

Giffords’s southern Arizona district, which is on the Mexican border, is widely considered a swing district, and several candidates of both parties have expressed interest in running for the seat.

In the end, Giffords did what was in her best interests and those of her constituents, said Fred DuVal, a friend and Democratic operative from Phoenix.

“It feels like a responsible decision in the sense that her health comes first, her recovery first,” he said. “And, secondly, knowing her so well, she’s not capable of making a commitment that she can’t engage with full talent and responsibility. I’m sure she balanced that and always wanted to do right by the people she represents.”

Before the shooting, Giffords had been a rising star in the Democratic Party, a centrist politician and talented communicator who championed stronger border security, veterans’ rights and solar energy. In its aftermath, she became a national symbol for the effort to restore civility to American politics, following a brutal 2010 midterm election in which even Giffords’s race turned into a bitter battle.

A peacemaker

Lawmakers set aside their partisan divisions to sit together for last year’s State of the Union address — before the legislature dissolved again into gridlock over the budget. Giffords served as a sort of peacemaker for the body in August, when she made a surprise appearance on Capitol Hill to vote in favor of raising the nation’s debt limit, with members on both sides of the aisle bursting into applause, many choking up or openly crying. Some stood on their chairs to get a glimpse of her.

At the end of September, Giffords had $879,000 in her campaign account, money that was raised almost entirely by the efforts of her close friends in Congress, including Rep. Debbie Wasserman Schultz (D-Fla.) and Sen. Kirsten Gillibrand (D-N.Y.).

Giffords by law cannot use that money for personal expenses, but she could transfer it to the Democratic Party for use in the special election or donate it to a charity. She could also keep the funds in that account for a future political race.

In a news release on Sunday, Giffords’s office said she would meet privately Monday with some of the people who were at the community meeting with her last January when the shooting occured. In addition to fellow survivors, some of the “citizen heroes” who aided the injured and subdued the gunman will be present, the congresswoman’s office said.

Gifford was also scheduled to meet with and than community leaders from her district, and some of her advisers. In late morning, she will visit a community food bank in Tucson to tour a family assistance center that bears her name.

Giffords will submit her letter of resignation to House Speaker John Boehner and Arizona Gov. Jan Brewer later this week, her office said.

Staff writer Felicia Sonmez contributed to this report.