According to The Associated Press and Washington Post, police arrested Dr. Regan Nichols on Friday and charged her with five counts of second-degree murder.
One of the patients, Sheila Bartels, reportedly died after overdosing on painkillers in 2012. The Post reported that on the day Bartels was discovered dead, she had filled a prescription for 510 pills.
The AP also reported that Nichols "prescribed more than 3 million doses of controlled dangerous drugs from 2010-2014" and in 2010 "prescribed one 47-year-old patient a total of 450 pills."
"Nichols prescribed patients, who entrusted their well-being to her, a horrifyingly excessive amount of opioid medications," Oklahoma Attorney General Mike Hunter said, according to the AP, adding that her "blatant disregard for the lives of her patients is unconscionable."
Nichols was released from prison on $50,000 bail.