In October 2012, a U.S. Border Patrol agent fired through the 20-foot steel fence separating Nogales, Arizona from Nogales, Mexico, killing an unarmed 16-year-old Mexican boy with 10 bullets through his body. The agents said he was throwing rocks. This was not an isolated incident by a rogue agent, but just the latest in a string of cross-border shootings that raise questions about oversight and accountability of the U.S. Border Patrol. In the last three years, Border Patrol agents have killed 6 Mexican citizens on their native soil, firing through the border to threaten and injure even more. One man was shot while picnicking with his family on the banks of the Rio Grande. Another 15-year-old boy was hit between the eyes with a bullet for allegedly throwing rocks. None of these cases has led to any known disciplinary action or criminal charges against the border police, and U.S. courts have rejected claims made by victims' families, asserting that Mexican citizens do not have the same constitutional protections as U.S. citizens. Fault Lines travels to the border town of Nogales - presently the nexus for this increasingly lawless law enforcement - to meet the families who have lost their sons at the hands of U.S. agents with no follow up or acknowledgement from U.S. officials.