I’ve updated the interactive map

Six years ago Felipe Calderón declared war on the drug cartels soon after taking office by sending troops to his home state of Michoacán. Six years later the war still rages on as Enrique Peña Nieto starts his term of office, and everyone is taking a look at the legacy of the man who started the war.

During 2007 and 2008 the Mexican state of Sinaloa had more drug war-related homicides than total homicides. This should in theory be impossible since drug war homicides are a subset of total homicides. How did this happen?

Note the log scale and that data are incomplete

The INEGI finally released homicide data at the municipality level, analyzing it by state turned out very similar results to the preliminary data released back in August, so I won’t repeat the state level charts I did back then, instead I will focus on the trends in violence at the metro area or big municipality level since both Tijuana and Ciudad Juárez had big declines in homicides —though they are still very violent— and Monterrey, Acapulco and Veracruz saw big increases.

I’ve written before about how the deaths of the Acteal massacre weren’t registered as homicides in the mortality database and about the large number of deaths of unknown intent in Ciudad Juárez. There’s actually another large error in the database that occurred in January and February of 2007. Lots of accidents of unspecified injury mechanism were registered in the Federal District at the same time there was a never before seen drop in the number of homicides.

Photo Credit: Jesús Villaseca Pérez

Ever since March 2008 Ciudad Juárez began to register an alarming number of homicides becoming Mexico’s most violent city. According to the Mexican vital statistics system Ciudad Juárez (coterminous with the Juárez municipality) went from having just 202 murders in 2007 to 1,616 in 2008, 2,397 in 2009, and 3,686 in 2010.

Mexican and US officials explain the dramatic increase in violence as due to a conflict between the Sinaloa and Juárez Cartels. After a new governor was elected in October 2010 Ciudad Juárez does seem to have started turning around, but it is still an extremely violent city.

Recently the Mexican government released to the public the final homicide data for 2010, and as you can see from the chart Mexico has suffered from a steep rise in homicides since 2008, and in 2010 reached the highest homicide rate in recent history.

I’ve written before about how I couldn’t find the Acteal Massacre in the homicide database available at the INEGI. So I decided to check if the deaths that occurred as a consequence of the massacre were misclassified as other types of violent death,

I’ve been complaining about how homicide statistics from police sources were too low in 2009, with the entire state of Chihuahua having less homicides than its biggest city. I was thinking of finding out if I could use the IFAI (Freedom of Information Access) to obtain the original CIEISP forms which the state police forces are supposed to fill out each month and send to the National System of Public Security (SNSP) for tallying, to see if there were any unusual patterns, but someone beat me to requesting the data.

You can see the request here, and download the excel file with the CIEISP forms here.

The main difference between the datasets is that the CIEISP forms usually report lower numbers than the data the SNSP gave to the ICESI. This is not surprising since the CIEISP forms have no recorded homicides in some states during the last months of the year (the request was made in December 2009), but the numbers for Chihuahua in both datasets are identical, with a total of 2523 homicides recorded. More importantly, in the months of November and December there were no homicides registered in the CIEISP forms, and the data for October looks incomplete. That’s the reason Chihuahua had such a low homicide rate according to the police, the data they gave to the ICESI only includes 9¾ months of homicides.