Brian A. Terry (Photo: U.S. Customs and Border Protections)

A U.S. Border Patrol agent was shot and killed along the Southwestern border last week, marking the second time in as many years that an agent was gunned down along the border with Mexico.

The shooting prompted politicians from both parties, including Arizona Gov. Jan Brewer and Department of Homeland Security Secretary Janet Napolitano, to emphasize the dangers faced by the 20,000 Border Patrol agents and thousands of other law enforcement officers who patrol the border.

Records from a police memorial group and the federal government paint a clearer picture of how violent the border truly is. Fourteen Border Patrol agents have died since 2006, and records obtained by USA TODAY show that agents shot and killed 20 people in that time.

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Lt. Jeff Palmer, who founded the Pima County (Ariz.) Sheriff's Office border crime section, said they face armed smugglers, constant assaults by immigrants throwing rocks and a rugged terrain that makes apprehending people, and defending yourself, extremely hard.

"It's a violent, violent place out there, and people are utilizing whatever means they can to avoid apprehension," Palmer said.

Border Patrol agents deplane Dec. 9 on Tohono O'odham Reservation in Arizona looking for drug smugglers. (John Moore, Getty Images)

Christian Ramirez of American Friends Service Committee, a Quaker organization that tracks border violence, said the blame lies on both sides of the border. Ramirez said smuggling cartels trying to push their goods into the U.S. are clashing with an ever-expanding collection of law enforcement officers on the U.S. side, leaving illegal immigrants simply looking for work caught in the crossfire.

"Border Patrol responds with more arms, more personnel, and drug cartels respond in kind. It's a cycle of violence that we need to figure out how to stop," he said.

A total of 260 agents fired their weapons in 213 incidents from 2006 to 2010, wounding 37 people, according to a database obtained from Customs and Border Protection through the Freedom of Information Act. The records reflect all Border Patrol encounters around the country, but Customs spokesman Lloyd Easterling said most of those occurred along the U.S.-Mexican border.

Fourteen Border Patrol agents died in the line of duty during that time period, according to the Officer Down Memorial Page, which tracks the deaths of law enforcement officers. Two died from gunshot wounds, the rest of various causes ranging from heat exhaustion to being intentionally struck by a car.

Jennifer Allen, executive director of the Border Action Network, a Tucson-based civil rights group that helps immigrants, said the numbers show that agents are being reckless when responding to illegal immigrants crossing the border.

She said she understands that drug cartels and human smugglers can be violent, but she said agents are approaching any illegal immigrant crossing into the U.S. with a "heavy handed" approach that leads to so many deaths and injuries.

Hipolito Acosta, who patrolled the border for several federal agencies before retiring in 2005, said the number of immigrants killed or wounded was low considering the dangers and activity levels along the border. He said they encounter so many dangerous situations with smugglers that they must approach every encounter expecting the worse.

"If you look at the narcotics interdictions along the border, if you look at the number of weapons that are found, that's not a high number," Acosta said.

Allen said she has long complained to Border Patrol officials that they need a more comprehensive training program so agents know how to better distinguish between armed smugglers and people looking to enter the country to live and work.

A 2007 report from the U.S. Government Accountability Office found that the Border Patrol "exhibits attributes of an effective training program." But it found that the ratio of young, inexperienced agents to experienced supervisors was often too high.

Easterling said they have focused on hiring more experienced supervisors and trainers to show the new agents how and when to use deadly force. He said agents are frequently outmanned by smuggling operations.

"We don't want any of this going on, clearly," he said. "But we realize that these organizations are not giving up without a fight. In defense of themselves, their partners and innocent third parties, our agents will respond."