The grisly discovery of the corpses of four women and one man earlier this month in an apartment in a quiet neighborhood in Mexico City could easily have been brushed off as yet another violent crime in a country engulfed in a protracted "war on drugs."
But there is a more sinister undertone to the killings.
The dead were not gun-wielding drug barons. So far, the only two victims publicly identified by the authorities are photojournalist Rubén Espinosa Becerril, 31, and human rights activist Nadia Dominique Vera Pérez, 32. Both fled eastern Mexico's Veracruz State after facing continuous harassment for their work and criticism of the authorities.
Their killings are only the latest in a long line of similar murders aimed at silencing journalists and other critics. Veracruz stands out for its recent history of unprecedented violence against journalists. Since 2011, 14 journalists have been killed there, three of them this year alone. All these cases remain unsolved. The investigations are plagued with shortcomings, including a reluctance to even acknowledge that the victims were journalists; that their violent demise may in some way have been linked to their work.
Mexico City's Attorney General, Rodolfo Fernando Ríos Garza, confirmed to radio outlets that Rubén Espinosa, Nadia Vera and the other victims were shot point-blank in the head. It is what the crime shows on TV refer to as "execution style". So far, one suspect is in custody, pending further investigation.
The authorities must investigate if any of these five people were gunned down to silence their journalism or human rights work, and inform the Mexican society of their findings. But regardless of whether or not it was designed to curtail freedom of expression or the work of human rights defenders, this violent crime must not go unpunished.
Such crimes are endemic across Mexico. One hundred journalists were violently killed in the last 15 years according to the National Commission on Human Rights.
Meanwhile, the UN High Commissioner for Human Rights reported 245 attacks, including 22 killings, against human rights defenders from 2006 to 2012.
Despite the gravity of this crisis, the Mexican authorities continue to fail to take concrete and effective measures to protect people like Rubén Espinosa and Nadia Vera. In 2012, the Mexican Congress unanimously passed the Law for the Protection of Human Rights Defenders and Journalists, which established a federal mechanism for their protection. Yet, most of those most at risk actually distrust this mechanism because it has proven ineffective. After more than three years, the government has yet to prove its will to ensure the law is effectively implemented.
A protection mechanism is not the solution, but it's a start. The state must also have a policy to prevent and mitigate risks and a clear plan to ensure that society at large understands and appreciates the vital and legitimate work of journalists and human rights defenders.
Likewise, all such cases, including that of Rubén and Nadia, must be properly investigated by civilian authorities. The most effective way to prevent similar attacks from happening again is to punish those who are found responsible and send a clear message that these attacks are not tolerated.
Before their killings, both Rubén Espinosa and Nadia Vera publicly expressed fears about what might happen to them. In an interview with an online media outlet a few days before his death, Rubén said the violence against journalists in Veracruz is what prompted his move to Mexico City.
After Nadia Vera's death, her mother -- poet Mirtha Luz Pérez- wrote to her:
Do not leave me without your eyes
Do not leave me without your voice
Do not leave me without your light
In the dark
Mexicans want to be free to express themselves, to question, to be creative. But this becomes impossible if any dissent is allowed to be expunged by violence. Either through killing them or cowing them into silence, this can only lead us to an environment where reliable independent journalists and human rights defenders are no longer there to inform society and spark debate.
This kind of crime deeply saddens us, but, what's worse, it spreads fear. As ordinary Mexicans, we deserve better. We deserve to see justice delivered. We are not going to be left blinded, silent and in the dark.