the enemies of the sino lowa cartel. >> of the seven major mexican cartels, the sina lowa cartel is consideredsive tentacles, extending deep into every corner of government, banking, and private industry. it's rivals, the tijuana cartel, the gulf cartel, the juarez cartel, the belta leifia, la familia mish la canna and the particularly murderer rosettas. >> in your work, you've uncovered some embarrassing and incriminating associations or connections between very high elected officials. the presidents and entire administrations and acts of incredible criminality. how did that change your life? >> well, when i start to make this investigation in 2005, and i really understand that it would be very dangerous, i have to say that it wasn't really a surprise for me what happened after i publish my book. what i didn't expect is that the threats came from the federal government. >> anna bell says that one of her sources said that the biggest threat was from within. that one of the most highly placed most senior law enforcement officials in mexico, had ordered her killed. >> because in my book, i put h