(NewsNation) — A Pennsylvania nurse is facing dozens of new charges for allegedly administering lethal doses of insulin to patients in her care.

Pennsylvania Attorney General Michelle Henry announced the new charges against Heather Pressdee, 41, who was previously charged with mistreating three patients. The new charges are regarding the alleged mistreatment of 19 patients at five different facilities between 2020 and 2023.

The charges include two counts of first-degree murder, 17 counts of attempted murder and 19 counts of neglect of a care-dependent person. The new charges bring the total number of patients Pressdee is accused of harming to 22.

The 17 counts of attempted murder apply to cases where the patient survived or the exact cause of death could not be determined.

“The allegations against Ms. Pressdee are disturbing. It is hard to comprehend how a nurse, trusted to care for her patients, could choose to deliberately and systematically harm them,” said Attorney General Henry. “The damage done to the victims and their loved ones cannot be overstated.”

According to prosecutors, Pressdee administered excessive amounts of insulin to patients in her care, some of whom had diabetes and some who did not. A total of seventeen patients Pressdee cared for died.

Pressdee allegedly administered the insulin during overnight shifts with lower staffing where patients would be less likely to be hospitalized immediately. The victims range in age from 43 to 104.

Court documents state the investigation into Pressdee uncovered a pattern of behavior where she would be accused of abusive treatment at a facility and then resign or get fired. The complaint also notes that if Pressdee thought a patient would survive, she would either administer more insulin or cause an air embolism to ensure their death.

Pressdee is accused of committing the crimes while working as a nurse at five Pennsylvania facilities: Concordia at Rebecca Residence, Belair Healthcare and Rehabilitation, Quality Life Services Chicora, Premiere Armstrong Rehabilitation and Nursing Center and Sunnyview Rehabilitation and Nursing Center.

Pressdee was arraigned Thursday, though it is not clear how she pleaded. She is being held without bail at the Butler County Prison.