"The attacks on the Blair House and later on the Capitol in the 50's were carried out by the Puerto Rico Nationalist Party, as part of an ill-fated revolt that was to occur on the island."
And most of this bunch were pardoned by Jimmy Carter in the late 70's."
There was another deadly ambush of a military van full of unarmed sailors around 1980 I believe. The "brave" terrorists machine-gunned the sailors trapped in the van and fled, killing several. I don't remember the details.