Ayotzinapa: EAAF Report on Evidence Found in the Cocula Landfill


At a press conference held today in Mexico City, the Argentine Forensic Anthropology Team (EAAF) unveiled its comprehensive expert report on the evidence found in the Cocula landfill, in the context of the investigation into the forced disappearance of 43 student teachers from Ayotzinapa. After more than one year of independent scientific work, EAAF has concluded that from the standpoint of physical evidence collected and analyzed from the Cocula landfill, it is not possible that the alleged perpetrators cremated the 43 students in that location because the physical evidence is not consistent with the testimonial evidence.

EAAF is an institution with more than 30 years of experience that has unanimous recognition in the region for its scientific rigor. EAAF has been involved in the investigation of the Ayotzinapa case since October of 2014 at the request of relatives of the missing students. Their participation was formally endorsed by the President, Enrique Peña Nieto, who promised to provide conditions for their work in one of the agreements signed with the family a few weeks after the events. The participation of members of EAAF as independent experts has met all required legal formalities.

In preparing its comprehensive expertise, EAAF formed an interdisciplinary team composed of 26 experts in archeology, anthropology, criminology, forensic entomology and botany, ballistics, fire dynamics, interpretation of satellite images, forensic dentistry, genetics and bone trauma specialists. The EAAF experts are from Argentina, Mexico, United States, Colombia, Uruguay and Canada.

“From the evidence, EAAF does not support the official hypothesis of a fire that burned the 43 normalistas.” – EAAF

“The EAAF has found no scientific evidence to support the versions of the alleged detainees.”

“There are no scientific elements to connect the Cocula remains with those of Alexander Mora found in the San Juan river.”

As for the content of the dictum, in order to determine whether it was scientifically possible that the 43 students were incinerated in the Cocula landfill, EAAF incorporated both a site report as well as a lab report. From the interdisciplinary technical analysis in both cases, the EAAF concluded that the scientific evidence and testimonial evidence are not consistent; therefore, the hypothesis postulated by the Attorney General’s Office (PGR) is not supported.

Download the EAAF executive summary here (18 page PDF – Spanish language)

Key points regarding the alleged fire in the Cocula landfill:

The EAAF team does not support the hypothesis that there was a fire of the required magnitude and duration necessary to incinerate 43 bodies the night of September 26 to 27, 2014.

  • In examining the surrounding vegetation at the landfill, EAAF concluded that no signs of abundant fire were found in these plants.
  • In the Cocula landfill, along with the bone remains, nearby plants that had started growing between June and August 2014, months before Sept. 26, show no signs of fire, and had the fire occurred those plants would have been consumed by the fire.
  • EAAF experts analyzed 17 tree stumps located in the area of the landfill where the fire occurred according to PGR. These stumps showed no significant damage from heat exposure.

Key points regarding evidence of multiple fires in the Cocula landfill:

EAAF concludes that there have been multiple fire events in the Cocula landfill and the evidence collected cannot be tied to one single event.

  • The analysis of the subsoil layers showed that several layers contained soot, ash and charred remains, indicating that there had been multiple fires whose effects had been sedimented.
  • Satellite photographs confirm that fires had existed in the Cocula landfill since at least since 2010.


Key points regarding bone fragments recovered from the Cocula landfill:

The EAAF team so far has not been able to establish the identities of the skeletal remains recovered in the landfill of Cocula, no scientific evidence exists that the remains in Cocula are the 43 students.

  1. The existence of multiple fires over several years at the landfill affects the interpretation of biological and non-biological evidence recovered in this location, because of this, evidence recovered cannot be associated with one single event.
  2. All of the remains recovered in Cocula were severely altered by fire and consists mostly of thousands of small fragments. This made it extremely difficult extract information from them.
  3. Both forensic teams (EAAF and PGR) have jointly concluded that the vast majority of the remains from the landfill as well as from the San Juan river, are not suitable for genetic identification due to the level of damage they present.
  4. The only positive identification to date of the 43 students comes from a sample that the PGR indicated came from the San Juan river. To date EAAF sees no physical evidence linking the remains from the San Juan river with the Cocula landfill.
  5. With regard to the evidence collected from a bag allegedly found in Rio Cocula. including one bone piece identified as belonging to Alexander Mora Venancio, EAAF reiterates that there are serious doubts regarding the origin of the samples because the chain of custody of this evidence was not maintained.
  6. Dental evidence such as bridges or fixed partial dentures of sophisticated character were collected, combined with jaw fragments; which are not compatible with the clinical dental history of the 43 students and dental records that were accessible. This implies the presence of remains of people who are not the 43 students.
  7. Some of the alleged perpetrators reported having incinerated other people in the Cocula landfill, without mentioning that the respective remains were removed from the site.
  8. Human skeletal remains were located burned in a fire pit with traces of tires at more than 20 meters away from the landfill where according to PGR, incineration of students had occurred.
  9. Non-human remains were found – that is, animal remains – were found in the Cocula landfill.

“EAAF was not present when the bag with alleged remains was recovered from the San Juan river” – Miguel Nieva

“Important note: sample of the remains from the San Juan river was completely different from those of the Cocula landfill.” – M. Nieva EAAF

“It was not possible to establish if the majority of the fragments are human or animal” – EAAF

Key points on ballistic evidence analyzed by EAAF:

The EAAF team concludes that the ballistic evidence is not consistent with the testimonial evidence on which the official hypothesis was built.

EAAF found the following ballistic evidence in the Cocula landfill:

132 shell casings – both at the top of the landfill and at the bottom, which were fired by at least 39 weapons of various calibers mostly long guns.

This evidence contradicts the testimonial evidence because the alleged perpetrators reported having used their weapons at the top of the landfill and used exclusively handguns.

In addition, 42 shell casings of 2 calibers were found clustered together in conditions that suggest they were deliberately placed in the landfill, during an inspection when the location was left unguarded and in the absence of EAAF experts, November 15, 2014.

“Relevant: The PGR did not invite EAAF in the recovery of 42 shell casings on November 15, 2014 in the Cocula landfill.” – Miguel Nieva

In summary, after a rigorous technical analysis, EAAF concluded that the scientific evidence and testimonial evidence is not consistent, which indicates that in the landfill of Cocula the event could not have occurred as per the “historic truth” the PGR gave intending to settle the case of the disappearance of the 43 normalistas.

To the families of the students and their legal representatives, the expert opinion of the EAAF team is a fundamental contribution to find the truth of what happened to their children. The comprehensive report of the experts and together with the important work of the Interdisciplinary Group of Independent Experts (GIEI), shows that the Federal Government generated, in a precipitated, willful and revictimizing manner, a “historical truth” lacking sufficient and convincing scientific evidence. Under these conditions, again it evidenced in the Ayotzinapa case has not yet secured justice and truth.

“Further investigation into the Cocula landfill is a waste of time and not really investigating what happened.” – Santiago Aguirre

Faced with the scientific findings of EAAF, families of the missing and their representatives reiterate that it is essential to continue to deepen the research proposed by the GIEI, allowing their full participation in the investigation, which should include, among other things: possibility of interviewing soldiers who witnessed the incident. Also they reiterated that it is essential that those responsible for deceiving families and society as a whole with the fallacious “historical truth” be punished.

After the realization of new surveys on the landfill, fathers and mothers of the 43 missing students demand that instead of wasting time on testing hypotheses that are not scientifically viable, efforts need to be made by the authorities to focus on the exhaustion of the new lines of research and relaunching the search using the highest technology available, as both EAAF and GIEI have recommended.

The entire EAAF press conference from today, February 9 2015 can be seen here (Spanish):

Centro de Derechos Humanos Miguel Agustín Pro Juárez
EAAF Executive Summary (18 page PDF Spanish language)

About Author

Erin Gallagher is a multimedia artist, translator and writer for Revolution News.