On 1 March 1954, Capitol Police escorted four individuals from the Capitol after firing shots within the House Chamber.

Dolores “Lolita” Labron, Rafael Cancel Miranda, Andres Figuero Cordero and Irving Flores Rodriguez fired approximately 18 shots throughout the House from the upper right hand corner of the gallery, injuring five congressmen. The group cited recognition of the Puerto Rican Nationalist movement as the reason for their actions. Then Governor Luis Munoz Marin called the actions "lunacy" and pointed out that their organization, The Puerto Rican Nationalist Party, had attempted to assassinate him in 1950. Representatives Alvin M. Bentley (R-MI), Ben F. Jensen (R-IA), Clifford Davis (D-TN), George H. Fallon (D-MD), Kenneth A Roberts (D-AL) all survived gunshot wounds. In 1979, President Jimmy Carter pardoned the assailants for their assault in the House chamber.