A nurse at a Swiss nursing home has been sentenced to life in prison after admitting to the murders of 22 nursing home patients over a six-year period.

The victims of Roger Andermatt, 36, were primarily women between the ages of 66 and 95 years old. Andermatt either smothered them or administered lethal injection.

Andermatt said the murders were a way to end the patients’ suffering and added he believed he was acting compassionately. He was employed at the facility between 1995 and 2001 and said he and fellow nurses were overwhelmed by the workload.

In addition to the sentence of life in prison, Andermatt was ordered to pay the equivalent of nearly $63,000 to relatives of four of his victims and court costs of about $161,000.