[6][7] Following an anonymous tip about a possible mass grave on the ranch, the Buscadores Guerreros de Jalisco Collective, an activist group dedicated to searching for missing persons, arrived at the site on 5 March 2025 to investigate.

[1][8] On 10 March, Mexican President Claudia Sheinbaum described the findings as "terrible" and stated that both the governor of Jalisco and the Secretary of Security and Citizen Protection were addressing the case.

[10] On 20 March, Senator Marko Cortés (PAN) proposed the creation of an interdisciplinary team of national and international experts to investigate the events at Izaguirre Ranch.

[15] After search collectives discovered Izaguirre Ranch, Attorney General Alejandro Gertz raised concerns about irregularities in the state’s investigation on 19 March, which included the failure to track or identify fingerprints at the scene, improper recording and identification of evidence such as abandoned clothing and footwear, the failure to conduct a full site inspection, inadequate processing of vehicles—three of which were later identified as stolen—and the lack of immediate involvement by the Attorney General's Office (FGR) for crimes related to high-caliber firearms or organized crime.

[16][17] On the same day, Gertz accused the Jalisco State Prosecutor's Office of failing to send all relevant forensic reports and documents to the FGR, delaying the process of transferring the case.