Department of Homeland Security Secretary Janet Napolitano,

who will be in the Tucson area today and Friday, called it an "unconscionable act of violence against the men and women of the Border Patrol and all those who serve and defend our country."

"It is a stark reminder of the very real dangers our men and women on the front lines confront every day as they protect our communities and the American people," she said in a prepared statement. "We will leave no stone unturned as we seek justice for the perpetrators."

Arizona Gov. Jan Brewer

called for state flags to be flown at half staff in tribute to Terry. "Although we needed no reminder of the ever- increasing dangers along our southern border, this tragedy serves as stark notice that the threats facing all who serve in protecting our state and nation are real, and are increasing on a daily basis."

Sen. John McCain, R-Ariz.:

"The increased violence in the border region demands that Congress provide the necessary resources and personnel to ensure the safety of all Americans, especially Border Patrol agents stationed on the border."

Sen. Jon Kyl, R-Ariz.:

"Our nation is fortunate to have men and women in law enforcement who are willing to protect us at great danger to themselves. This act of violence is yet another upsetting reminder of the dangers along the southern border. The federal government must do more to secure the border and prevent future tragedies."

Rep. Raúl Grijalva, D-Ariz.:

"Neither we nor our neighbors want to see the border region become more dangerous, either for civilians or the brave men and women who protect them. This crime should not deter the many peaceful efforts under way to improve the quality of life for people on both sides of the border."

Rep. Gabrielle Giffords, D-Ariz.:

"This is a tragedy that deserves nothing less than the swiftest and strongest response. It is a stark reminder that our borders are not yet secure. What additional tragedies must Southern Arizonans endure before my colleagues in Congress and the Obama administration address this crisis with the full weight of our resources? We must act and we must act now."