A Pennsylvania nurse who administered lethal or potentially lethal doses of insulin to numerous patients pleaded guilty to three counts of murder and other charges Thursday and was sentenced to life in prison.

Heather Pressdee, 41, was given three consecutive life sentences and another consecutive term of 380-760 years behind bars during a hearing in Butler, about 30 miles (48 kilometers) north of Pittsburgh. She played a role in the deaths of at least 17 patients who lived in five health facilities in four counties between 2020 and 2023, prosecutors said.

The victims ranged in age from 43 to 104. Coworkers often questioned Pressdee’s conduct and said she frequently showed disdain for her patients and made derogatory comments about them, authorities said.

Pressdee pleaded guilty to three counts of first-degree murder and 19 counts of attempted murder. She initially was charged in May 2023 with killing two nursing home patients and injuring a third,. Further investigation led to dozens of more charges against her. During a February hearing in which she argued with her attorneys, she indicated that she wanted to plead guilty.