

Homeland Security Secretary Janet Napolitano (c.) tours the US-Mexico border with US Border Patrol agents in the Coronado National Forest near Nogales, Ariz., Oct. 30, 2011. Most illegal border crossers are apprehended along the 2,000-mile long Mexican border in California, Arizona, New Mexico, and Texas. Michael Chow/The Arizona Republic/AP
A woman shows an identification card to a US Customs official as she crosses into the United States from Mexicali, Mexico, in Calexico, Calif., Feb. 1, 2012. Thousands of Mexicans leave their homes each morning to become a pillar of one of most unusual and depressed labor markets in the United States. Gregory Bull/AP
An unidentified migrant from Honduras waits for a northern bound train during his journey toward the US-Mexico border on the outskirts of Mexico City, May 12, 2012. Every year, tens of thousands of Central American migrants embark on the dangerous journey through Mexico to try to cross into the US. Marco Ugarte/AP
An investigator inspects a crime scene where a 16-year old was shot in Nogales, Mexico, October 12, 2012. A US Border Patrol agent shot at suspected drug smugglers who were hurling rocks from Mexico across the border into Arizona, the agency said, and Mexican authorities said one of them, the 16-year-old, was killed. Reuters
A federal policeman guards the area where bodies were found on a highway to the US border found in the town of San Juan near the city of Monterrey, Mexico, May 13, 2012. Christian Palma/AP
Traffic moves along the border fence separating Nogales, Ariz., and Nogales, Sonora, Mexico, July 27, 2010 Jae C. Hong/AP
A man rides his bike through the Mexican port of entry in San Luis Rio Colorado, Mexico, on the other side of the border from the US city of Yuma, Ariz., on July 29, 2010. A US federal judge blocked the most controversial parts of Arizona's immigration law from taking effect. Guillermo Arias/AP
Demonstrators damage part of the US border fence, during a protest along the fence between Mexico and the US, on the outskirts of Ciudad Juarez, on June 12, 2010. The protest was against an incident, when a US border patrol agent shot dead a teenage boy near the border after a group of migrants threw rocks at officials. Alejandro Bringas/Reuters
Two woman walk along the US-Mexican border showing graffiti that reads 'the walls' in Nogales, Sonora, Mexico, on July 27, 2010. Jae C. Hong/AP
A US border patrol vehicle is seen from the Mexican side of the border while driving near Otay Mountain, June 6, 2010, on the outskirts of San Diego, Calif., in this long-exposure photograph. Jorge Duenes/Reuters
A chapel sits near the US-Mexico border at the Pinacate reservation, on the outskirts of San Luis Rio Colorado, Mexico, on July 29, 2010. Guillermo Arias/AP
Alondra Rojas participates in a protest held by the Border Network for Human Rights on June 22, 2010, in El Paso, Texas, following the border patrol shooting of Sergio Adrian Hernandez Guereca. Mark Lambie/The El Paso Times/AP
People embrace during the funeral of Sergio Adrian Hernandez Guereca at the cemetery in Ciudad Juarez, Mexico, June 10, 2010. Mexico condemned the fatal shooting of Hernandez Huereka by a US border patrol agent through diplomatic correspondence. AP
Demonstrators take part in a protest at the border crossing point in Nogales, Mexico, during the first official day of Arizona's controversial Senate Bill 1070 immigration law on July 29, 2010. The placard reads 'Do I look illegal? No SB1070'. Alonso Castillo/Reuters
US authorities from El Paso, Texas, inspect a tunnel near the border crossing between Mexico and the United States on June 25, 2010. Mexican and US border patrols discovered what could be a drug-smuggling tunnel on the banks of the Rio Bravo, according to local media. Alejandro Bringas/Reuters
A man waits in a line at the border to legally cross into Arizona from Nogales, Mexico, on April 28, 2010. The Mexican government warned citizens to use extreme caution if visiting Arizona because of a new law that requires all immigrants and visitors to carry US-issued documents or risk arrest. Gregory Bull/AP
The rising Rio Grande is seen under International Bridge No. 1 in Laredo, Texas, July 8, 2010. The dramatic rise of the Rio Grande caused by hurricane Alex and continuing rains forced the closure of the major border crossing and another crossing known as the Colombia Bridge, about 20 miles upriver. Edward A. Ornelas/San Antonio Express-News/AP
A border patrol vehicle sits along the border fence separating Nogales, Ariz., and Nogales, Sonora, Mexico, on July 28, 2010. Jae C. Hong/AP
A man peeks through the border fence to the United States from Tijuana, Mexico, on Feb. 19, 2008.
Sgt 1st Class Andy Kelemer of the Tennessee National Guard stands near the primary border fence area Yuma, Ariz., on March 2, 2007.
A US border patrol agent opens a metal door on the border between the United States and Mexico in San Isidro on Nov. 15, 2009. The Friendship Park on the Pacific Ocean between San Diego and Tijuana became a place where families and lovers divided by illegal immigration could unite briefly after it was opened in 1971.
Oscar, whose last name was withheld, charges 5 quetzales ($1) to ferry people across the Suchiate River to Guatemala on his innertube raft. The Suchiate River runs along the Mexican/Guatemalan border and is the crossing point for many Central American migrants heading to the United States.
Mexican Antonio Ocampo, a recently deported migrant from Seattle, waits for a chance to cross to the US near the border fence in Tijuana, on Sept. 24, 2009. Guillermo Aria/AP
Minuteman Project volunteer 'Randy' of Las Vegas, patrols the US-Mexican border on April 4, 2005, along a border road near Naco, Ariz. Members of the Minuteman Project say their mission is to stop the flow of illegal immigration, a job they say federal authorities are failing to do. Matt York/AP/File
US Customs and Border Patrol officer Daniel Serrato walks to the end of the six mile, 15-foot-tall fence that flanks the border entry port of Palomas, Mexico on May 13, 2009. Tony Avelar/The Christian Science Monitor
This undated picture provided by the US Customs and Border Protection shows a prototype of a tower for a virtual fence along the border at a test facility in Playas, N.M. US Customs and Border Protection/AP
Martin Gutierrez Lopez (2nd r.), a recovering drug addict, shouts after being baptized by evangelical pastors in the Bravo River at Ciudad Juarez, on the US-Mexican border, on April 11, 2009. Rodrigo Abd/AP/File
Border patrol agent Derek Gonzalez (l.) holds a pellet gun that shoots half-inch plastic tear gas projectiles used to retaliate against rock-throwing assailants on March 5, 2008.
Local resident Dawn Garner views Mexico through a new mesh fence on March 4, 2008. She is skeptical that the new fence being built on the US-Mexican border near Bisbee will be effective at keeping out illegal incursions. Robert Harbison/Special to The Christian Science Monitor
A man climbing over the landing-mat fence at the international border from Nogales, Sonora, Mexico, to Nogales, Ariz., May 31, 2006.
People converse in downtown Calexico, Calif., only yards from the Mexican border, April 30, 2008. The majority of people who live in Calexico speak Spanish, and storefront businesses are no exception. Mary Knox Merrill/The Christian Science Monitor
Daniel Santillan, community liaison for the Calexico Unified School District, verifies student residencies by visiting homes, April 29, 2008. He also photographs students at the port of entry that he suspects are illegally attending school.