A U.S. Justice Department inspector-general audit has found that the Sinaloa Cartel hired a hacker who in 2018 obtained an FBI assistant legal attaché’s phone records and geolocation data and infiltrated Mexico City’s surveillance-camera network. The information let the cartel track the agent’s movements, identify people meeting with him and, in some cases, intimidate or kill those potential informants, the report says. The breach occurred while the bureau was pursuing the case against cartel boss Joaquín “El Chapo” Guzmán. According to the audit, the hacker offered a “menu of services” that included manipulating mobile devices and exploiting other electronic systems. The report does not name the hacker, the agent or the victims, nor does it specify how many people were killed. The findings form part of a broader review of how the FBI protects sensitive operations from what the watchdog calls “ubiquitous technical surveillance.” The inspector general issued four recommendations—ranging from clearer lines of authority during cyber incidents to expanded training—which the FBI accepted. In Mexico, the capital’s C5 public-safety command said it has no evidence of a recent compromise of its camera network, adding that any intrusion would have taken place in 2018 under a previous municipal administration. City officials said cybersecurity measures and camera systems have since been overhauled. The episode highlights the growing technological sophistication of Mexican criminal organizations and points to continuing vulnerabilities in U.S. law-enforcement operations overseas.