Revisits the 2010 death of Anastasio Hernández-Rojas, an undocumented Mexican immigrant who died while in custody at the border. When eye-witness video emerges, it sparks a far-reaching investigation from a border checkpoint to Washington D.C. CRITICAL INCIDENT chronicles journalists’, lawyers’, and family members’ efforts to explore the Border Patrol’s involvement in the incident, ultimately pointing to cover-ups, and uncovering the existence of a little-known unit inside the agency that had been involved in other border related incident.