CIUDAD VICTORIA, Mexico -- Claudia Pardo Garca was traveling with her husband and five children when she heard the rotors of a police helicopter hovering above their vehicle in the Mexican border city of Matamoros.

Minutes later, her 7-year-old daughter had been shot in the head.

Aranza Aidelany Pardo, who held dual U.S. and Mexican citizenship, was among six people killed Oct. 29 during a security operation targeting an alleged member of the Gulf Cartel and roadblocks erected by the criminal group afterward.