"Mexican drug trafficking organizations (DTOs) pose the greatest crime threat to the United States, according to the U.S. Drug Enforcement Administration's (DEA's) National Drug Threat Assessment published in October 2017. These organizations have for years been identified for their strong links to drug trafficking, money laundering, and other violent crimes. These criminal groups have trafficked heroin, methamphetamine, cocaine, marijuana, and, increasingly, the powerful synthetic opioid fentanyl. U.S. overdoses due to opioid consumption sharply increased to a record level in 2016, following the Mexican criminal syndicates expanded control of the heroin and synthetic opioids market. The major DTOs and new crime groups have furthered their expansion into such illicit activity as extortion, kidnapping, and oil theft that costs the government's oil company more than a billion dollars a year."
CRS Report for Congress, R41576