>I would not have believed that a US government agency was capable of assassinating an American
Go find the book “The Praetorian Guard” by John Stockwell. It’s out of print but the torrents are available. There’s a chapter devoted to the assassination. It’s a short read, ~200 pages, loaded with info and references.
Ha! It’s on archive.org
https://archive.org/details/JohnStockwellPraetorianGuardPt1
Thanks for that URL to “The Praetorian Guard” online.