Last Thursday, nine dead bodies were hanged from a bridge in Mexico, and it's believed the grisly scene was meant to be a scare tactic by a cartel.
At least 82 candidates and officeholders have already been killed since September.
Their family still hopes to find them alive.
Andrés Manuel López Obrador has jumped to an early lead, but not everyone is happy about his stance on the cartels.
Mexico's avocado producers are prime targets for cartel extortion.
The warning may have a serious impact on Mexico's economy.
In the first six months of 2017, Cancún has seen more killings than in the whole of 2016.
Armed, masked men in the mining region set up the vigilante group and formed a roadblock in response to extortion and kidnappings.
Mexico is one of the deadliest countries for journalism at a time when murder rates are at their highest since 2011.
The government's fight against criminal cartels accounted for 23,000 deaths in 2016.
The Mexican drug kingpin spends up to 23 hours locked up and is not allowed to receive any visitors.
Filming for the series has been shrouded in secrecy, and Guzmán has launched legal appeals in Mexico against the producers.
Mexican investigators announced the discovery of more than 250 skulls from unmarked graves in the eastern Gulf state of Veracruz.
Guzman was one of the world's most wanted drug kingpins until he was captured in January 2016. Six months earlier, he had broken out of a high-security penitentiary in central Mexico through a mile-long tunnel.
The discovery was made in Guerrero, a state plagued by violence in southern Mexico.