The Sinaloa drug cartel in Mexico hacked the phone of an FBI official investigating kingpin Joaquín “El Chapo” Guzmán as part of a surveillance campaign “to intimidate and/or kill potential sources or cooperating witnesses,” according to a recently published report by the Justice Department.

The Mexican Sinaloa drug cartel hired a hacker to track and surveil the FBI, then used that information to intimidate and even kill witnesses.

A hacker hired by a notorious Mexican drug cartel reportedly accessed an FBI official’s phone records and surveillance cameras to help find and kill FBI informants.