On 1 March, five members of the US Congress were wounded in the House of Representatives by four Puerto Rican independence supporters who fired at random from a spectators’ gallery.
Richert, Lucas Paul. "Shooting in the House of Representatives". The Literary Encyclopedia. First published 01 November 2008
[http://www.litencyc.com/php/stopics.php?rec=true&UID=5641, accessed 25 May 2015.]