Territory battles between gangs over new customers attracted by cheap heroin have resulted in terrible consequences for those caught in the crossfire.
Two dozen members of Sinaloa arrested weeks after El Chapo was recaptured, U.S. authorities say.
In the short term, capturing the world's most notorious drug lord may lead to more violence.
Mexico's attorney general told a newspaper there are reasons to believe Kate del Castillo may have used Guzman's money to help fund her tequila business.
With Chapo behind bars, it falls to Zambada to maintain the Sinaloa Cartel's ranking as the world's largest.
Mexican authorities have formally begun extraditing the cartel leader to the U.S.
In Mexico's northern states, life expectancy fell by as much as three years.
The vote does not legalize marijuana consumption, but more rulings of the same kind could set a legal precedent.