On 13 March 2012, the Mexican Senate approved an amendment to the law that would make any attack on journalists a federal crime.
If you're wondering why that might be important, you should consider the case of Miguel Ángel López Velasco, a columnist for the Veracruz-based newspaper, Notiver.
On 20 June 2011, a few days after publishing an article on drug trafficking in Veracruz State, López was shot to death at his home. His wife and son were executed alongside him. The main suspect in the killing is a former state police officer.
You might also think about Osvaldo García Íñiguez, a manager at the business daily El Financiero. He disappeared whilst travelling to Guadalajara on 14 November 2011. The last call he ever made was a panicky message to colleagues, telling them that he was being tailed by two police patrol cars.
In both these cases, uniformed state employees (or former state employees) are the key suspects and local state authorities are charged with investigating the crimes; there have been no prosecutions, no arrests. These cases are the tip of the iceberg.
Mexico is one of the most dangerous countries in the world in which to be a journalist. Since 2006, at least 45 reporters have been murdered or have 'disappeared' in connection with their work. The drug cartels are believed to be behind the majority of these crimes, but police officers and other state employees are implicated in many of them.
Those who attack or murder journalists do so brazenly and with relative impunity: since 2000, there have been less than a handful of convictions for these crimes.
This is largely because the vast majority of attacks on journalists are investigated at state level, where the Mexican authorities are under-resourced, often inept, and at their most corruptible: bribery and threats ensure that crimes aren't investigated too thoroughly.
Sometimes, though, it isn't even necessary to bribe or threaten the local officials. Sometimes, they're already 'employees' of criminal gangs. The drug cartels have been known to 'hire' young men long before they go to college and then sponsor them through police training; practically every class of fresh police graduates contains someone with cartel connections.
In some states, the corruption of the local authorities is almost total. In December 2011, the Veracruz municipal police force was considered so rotten that it had to be disbanded altogether; law enforcement was handed over to the Mexican navy. The previous month, an armed gang had assaulted the offices of the Veracruz-based El Buen Tono. The gang members were so unconcerned about the local police that they didn't even bother to hide their faces, despite everything being recorded openly on security cameras.
The federalization of attacks on journalists is a key issue on which PEN International, the global writers and free expression organisation, has long campaigned. By taking investigations into attacks on journalists out of the hands of individual states and giving overall responsibility to the federal authorities, cases will be less susceptible to the corrupting influences that are so rife at the local level.
At the moment, empowering the federal authorities offers the only realistic hope for ending the climate of impunity that exists in Mexico for those who attack journalists.
There have already been steps in the right direction: since 2006, an extra 30,000 federal officers have been employed, many of whom have been put through a strict vetting regime consisting of drug and polygraph tests, and psychological and background checks. By 2013, more than half of all federal officers will have been vetted in this way.
The amendment passed by the Senate on 13 March has been fought over and debated since 2008. It now needs to be passed by a majority of states to become law. That will require another fight, but Senate leaders believe that it will be won before the summer.