El Halconazo (Spanish: The Falcon Strike) was a massacre of student demonstrators by members of the Halcones, a state-sponsored paramilitary group, on 10 June 1971 in Mexico City.

In April 1971, the press spoke of coming reforms in education and soon figures such as José Revueltas and Heberto Castillo, both jailed for two and a half years, resurfaced in the political arena.

Days before the demonstration many police vehicles and cars started making regular runs near the Casco de Santo Tomás (one of the IPN's main campuses).

[1] The march started at the Casco de Santo Tomás, and proceeded through Carpio and Maestros Avenues so the protesters could take the Mexico-Tacuba Causeway, and eventually end up at Zócalo.

The support included extra weapons and makeshift transports, such as civilian cars, vans, police vehicles and an ambulance from the Cruz Verde (an organization similar to the Red Cross).

[1] Alfonso Martínez Domínguez, then-Mexico City governor, and Julio Sánchez Vargas [es], attorney general, denied that there were Halcones and police chief Escobar blamed the students for creating extremist groups within their movement.

The Halcones were a Mexican paramilitary group created in the late 1960s and led by Colonel Manuel Díaz Escobar, then deputy director of General Services of the Federal District Department.

[2] In 2005, there was discussion in Mexico as whether the statute of limitations for the crimes committed in the Corpus Christi Massacre had expired or the criminals could still be judged responsible.

[3] Mexican filmmaker Gabriel Retes produced, directed, and acted in a film titled El Bulto (The lump), where he portrays Lauro, a photojournalist, who was attacked by a Los Halcones member and left in a coma.