MADISON, Wis. (WTVO) — Dawn Drum, 54, has pleaded guilty in federal court to tampering with medication at St. Mary’s Hospital in Janesville.

According to the U.S. Department of Justice, in November 2021, Drum withdrew fentanyl from vials and replaced the drug with saline, resealing the vials with superglue. She then placed the tampered vials back into an automated medication dispensing system, which made them available for patient use.

Drum’s crime was discovered when an audit was conducted by the hospital, after her fentanyl overrides and waste were “excessive” compared to other employees, the DOJ said in a statement.

When management confronted Drum in November 2021 and asked her to take a drug test, she refused and resigned her position, authorities said.

She was sentenced to spend 18 months in prison and was fined $30,000.