The two Homeland Security agents were driving on a notorious stretch of road called Highway 57 deep in country controlled by the brutal Los Zetas cartel in February 2011 when their armoured car was rammed off the road.
Their vehicle malfunctioned and the cartel gang managed to insert the barrels of an AK-47 and a handgun through a two-inch opening of the passenger window and began firing.
Special agent Jaime Zapata was fatally wounded and died at the scene. He was the first US special agent to be murdered in the line of duty in Mexico for more than a quarter of a century.
His partner Victor Avila was seriously wounded but managed to call for help and later recovered.