On October 24, 1935, police fired on Nationalists at the University of Puerto Rico in Río Piedras, killing four Party members. Colonel Francis Riggs, the U.S.-appointed police chief, promised "war to the death against all Puerto Ricans." In February 1936, two young Nationalists, Hiram Rosado and Elías Beauchamp, assassinated Riggs in San Juan; arrested and taken to police headquarters, both were summarily executed inside the station without trial.
No officer was ever prosecuted for the killings. Beauchamp's final gesture — a cadet salute captured by a photographer moments before his death — became an icon of the movement, and the paired atrocities of Río Piedras and the station-house executions convinced a generation of Nationalists that the colonial state would never permit a lawful road to independence.