Army tested 'germ warfare' on NYC subway (2015)
Horrific, yet sadly not the only time the US government has used bio weapons on their own population.The most well known examples are MKUltra: https://en.wikipedia.org/wiki/MKUltraAnd the Tuskegee Syphilis Study: https://en.wikipedia.org/wiki/Tuskegee_Syphilis_StudyIf you want to look at something slightly more speculative, I recommend Dr. Mary's Monkey: https://www.amazon.com/Dr-Marys-Monkey-Cancer-Causing-Assass...It talks about how the CIA worked with Dr. Mary Sherman and Dr. Alton Ochsner to develop a cancer causing bio-weapon intended to give Castro cancer, but ultimately became part of the plot to assassinate JFK when that fell through.