Federal prosecutors have charged a former nursing assistant at a medical center for veterans in West Virginia with seven counts of second-degree murder.

Reta Mays, who worked at the Louis A. Johnson Veterans Affairs Medical Center in Clarksburg, is accused of killing seven patients by injecting them with insulin. She is also charged with assault with intent to commit murder regarding an eighth patient.

Mays worked the night shift from 2015 to 2018 at the medical center, in a ward that housed many patients who had diabetes, according to the charging documents.

In 2018, prosecutors say a doctor reported "a concern about the deaths of patients who had suffered unexplained hypoglycemic episodes," a condition linked to a surplus of insulin in the body. Some of these episodes involved patients who were not diabetic.

That report led to an investigation and culminated in the federal charges filed Monday in U.S. District Court in West Virginia.

Mays is scheduled to appear in federal court on Tuesday at 2 p.m. ET.

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