Fatal shootings by U.S. Border Patrol agents were once a rarity. Only a handful were recorded before 2009. Unheard of were incidents of Border Patrol agents shooting Mexicans on their own side of the border. But a joint investigation by the Washington Monthly, The Investigative Fund at The Nation Institute, and the television network Fusion has found that over the past five years U.S. border agents have shot across the border at least ten times, killing a total of six Mexicans on Mexican soil. A former Clinton administration official who worked on border security issues couldn't recall a single cross-border shooting during his tenure. “Agents would go out of their way not to harm anyone and certainly not shoot across the border,” he said. But following a near doubling of the number of Border Patrol agents between 2006 and 2009, a disturbing pattern of excessive use of force emerged. For “Over the Line,” we traveled to several Mexican border towns, tracking down family members of victims, eye-witnesses to the shootings, amateur video, Mexican police reports, audiotapes, and autopsies to recreate the circumstances surrounding these cross-border killings. We recount the stories of several of them, including 16-year-old José Antonio Elena Rodriguez, a studious Mexican teen who dreamed of becoming a soldier to fight the violence that plagued his hometown of Nogales, Sonora, and who was shot and killed by U.S. border agents as he walked to pick his brother up after work. The first two shots were to the boy's head; he was shot eight more times as he lay, prone and bleeding, on the sidewalk. Although Border Patrol protocols and international treaties between Mexico and the United States appear to have been violated by these cross border shootings, none of the agents involved have yet been prosecuted. If any agents have been relieved of their duties for their role in the incidents, that information has not been made available to the public, and our queries to Customs and Border Protection on this issue have been denied. The Washington Monthly story was accompanied by two broadcasts that aired at the launch of the news network Fusion, a joint project of ABC News and Univision. These reports delve into two of the more troubling incidents in greater depth. “Investigation Shows Mexican Teen Was Shot 8 Times on the Ground” tells the story of Rodriguez, the teenager killed in Nogales; “U.S. Border Patrol Shoots and Kills Mexican Man in Park with Family” uses amateur video and eyewitness testimony to tell the even more shocking story of Arevalo Pedroza, shot and killed by US border agents who fired into a crowd of picnickers on the Mexico side of the Rio Grande in September 2012.