9. Donald Harvey
Donald Harvey was a former orderly in hospitals in Ohio and Kentucky during the 1970s and 1980s. During this time, he killed an estimated 37 patients. However, the real victim count is believed to be much higher as Harvey claimed the figure is closer to 70. His killing spree “began by accident” after hooking up a patient to an empty oxygen tank, and then he just couldn’t stop.
The cold-blooded killer never showed any remorse for his crimes. In one interview, he said, “Some of those (patients) might have lasted a few more hours or a few more days, but they were all going to die. I know you think I played God, and I did.”
In a chilling letter that he wrote behind bars, the serial killer joked, “Lord, Grant me the serenity to accept the things I cannot change, change the things I can, and the wisdom to hide the bodies of those people I had to kill because they pissed me off.”