Peru's Armed Forces were sent to overcrowded prisons where rebels led an uprising on June 18, 1986, killing an estimated 300-400 inmates, marking the most serious crime against humanity during the Alan Garcia administration.
The armed intervention came after members of Peru's Shining Path, imprisoned in the San Juan de Lurigancho facility — as well as the facilities of El Fronton Island and Santa Barbara women's prison — initiated a coordinated uprising to demand the release of some 500 political prisoners to coincide with the World Conference of the Socialist International led by President Alan Garcia Perez.
As negotiations broke down, the order was given to attack the prisons. The first assault began in the women's prison at Santa Barbara, where the Republican Guard demolished a wall and sent tear and paralyzing gases into the prison, killing two people.
At midnight, June 19, the assault on the prison on the island of El Fronton began. The attack was carried out under the command of the Peruvian Navy, where it was announced that the island was under the control of the Joint Command of the Armed Forces as it had been declared a restricted military zone. During the assault, about 135 prisoners were killed.
Simultaneously, a Republican Guard SWAT team arrived at Lurigancho prison and placed explosives around the outer wall of the Industrial Pavilion. A joint offensive by troops of the Republican Guard and the Peruvian Army followed. After heavy fighting with guns and grenades, the prisoners surrendered. Hours later, over 250 prisoners that had occupied the building lay dead: most had been executed, one by one, by a shot to the nape of the neck.
On Aug. 16, 2000, the Inter-American Court of Human Rights ruled that the Peruvian state was responsible for the assault, and ordered it to open an investigation that would properly determine and sentence the culprits.