WASHINGTON - Vice President Joe Biden, Speaker John Boehner and former Rep. Gabrielle Giffords were on hand Tuesday to dedicate a room in the Capitol Visitor Center to a congressional staffer slain two years ago in the Tucson attack that critically wounded Giffords and took six lives.

Gabriel "Gabe" Zimmerman, Giffords' community outreach director, was the only staffer ever killed in the line of duty, and Boehner pointed out that the meeting room named in his honor was the first room in the Capitol complex to be dedicated to a staff member. Zimmerman was 30.

Biden, like other speakers, referred to Monday's bombings at the Boston Marathon in telling the room full of family and friends that "at the most difficult times is when we stand closest together."

Giffords' husband, retired Navy Capt. Mark Kelly, speaking on behalf of Giffords, also recalled how Zimmerman ran toward the wounded congresswoman and other victims when a gunman opened fire at a gathering outside a Tucson supermarket.

"Putting himself in the service of others was his last act," Kelly said.

Giffords, who was shot in the head and still has difficulty speaking, was in Washington with her husband to urge the Senate to pass legislation aimed at reducing gun violence.

Others speaking at the ceremony included Zimmerman's parents, House Democratic leader Nancy Pelosi, Arizona Republican Sen. Jeff Flake and Democratic Rep. Ron Barber, another Giffords aide who was injured in the Jan. 8, 2011, shooting and later succeeded Giffords as the representative in the Southern Arizona district.

"Putting himself in the service of others was his last act."

Mark Kelly

Retired Navy captain and Giffords' husband