In 1931, Cornelius Rhoads, a North American pathologist at the Rockefeller Institute for Medical Investigations in San Juan, carried out a murderous "experiment" in which 13 Puerto Ricans died after being purposely infected with cancer. In a letter to another doctor, leaked to the Puerto Rican Nationalist Party, Rhoads wrote: "the Porto Ricans are beyond doubt the dirtiest, laziest, most degenerate and thievish race of men ever inhabiting this sphere. It makes you sick to inhabit the same island with them.… What the island needs is not public health work, but a tidal wave or something to totally exterminate the population. It might then be liveable. I have done my best to further the process of extermination by killing off eight and transplanting cancer into several more. The latter has not resulted in any fatalities so far.... The matter of consideration for the patients' welfare plays no role here - in fact, all physicians take delight in the abuse and torture of the unfortunate subjects".
When the case was brought to the press by Don Pedro Albizu Campos (the Nationalist Party President), the North American Governor of Puerto Rico had a prosecutor investigate the charge. Rhoads never denied writing the letter, but despite evidence proving that 13 patients had died, eight of whom were treated by Rhoads, the prosecutor exonerated Rhoads, calling him merely "a mentally ill person or a man with few scruples."
However, this "mentally ill person" went on to direct the establishment of US Army chemical warfare laboratories in Maryland, Utah, and the Panama Canal Zone, for which he was awarded the Legion of Merit in 1945. That same year, Rhoads was appointed to the staff of the US Atomic Energy Commission. The Commission was at that time carrying out radiation experiments on unwitting prisoners, hospital patients and soldiers.
Meanwhile, a 1950 Puerto Rican Nationalist insurrection led to the arrest of hundreds of activists, including Don Pedro Albizu. The prisoners later charged they were experimented on with drugs. According to Nationalist Party leaders, Rhoads was finally getting his revenge for Albizu's earlier murder charge. Albizu was denounced by US and local colonial officials as a lunatic, but doctors eventually supported his charges. His health steadily deteriorated, and he died shortly after his release from prison in 1965. Subsequent documents have supported both his original murder charges and his allegations of radiation poisoning.