The Forsyth County District Attorney Jim O'Neill said Jonathan Hayes administered lethal doses of insulin to two of his patients.
A third patient survived after receiving a near fatal dose.
The incidents happened between 2021 and January 2022 at Atrium Health Wake Forest Baptist Medical Center in Winston-Salem.
The hospital says it notified police when it discovered what was happening.
Investigators say Hayes was a "Rogue Nurse" who didn't know the patients before the incidents.
He was charged with two counts of murder and one count of attempted murder.
According to O'Neill, this is the timeline of the deadly doses:
- On December 1, 2021: Hayes administered a near-fatal dose of insulin to Pamela Little on Dec. 1, 2021 and Little survived.
- On Jan. 5, 2022: Hayes administered a lethal dose of insulin to patient Gwen Crawford, who died three days later.
- On Jan. 22, 2022: Hayes gave another lethal dose of insulin to Vickie Lingerfelt, who died five days later.
Hayes had been in nursing for 21 years and worked during the COVID-19 pandemic, according to the Winston-Salem Journal.
There is no motive at this time.