A former pharmacist from Milwaukee who’s been jailed for destroying more than 500 doses of the Moderna vaccine for COVID-19 has been identified by jail records, according to reports.

The suspect, who has since been fired from his job at the Aurora Medical Center in Grafton, Wisconsin, is accused of pulling 57 vials of the coronavirus treatment from the refrigerator and leaving them out overnight. He knew it would render the vaccines “useless” and lead people to believe they’d been vaccinated properly, police said.

While authorities have not yet officially released the suspect’s identity, Steven Brandenburg, a licensed pharmacist, was booked Thursday at the Ozaukee County, Wisconsin, jail on counts of criminal damage to property and second-degree recklessly endangering safety, according to the Milwaukee Journal Sentinel. The 47-year-old remained behind bars on Friday, but has not been formally charged.

Jeff Bahr, president of Aurora Health Care Medical Group, called the suspect a “bad actor” during a virtual press conference Thursday afternoon. He did not provide a motive.

The Aurora medical center said in a statement that the pharmacist admitted “to intentionally removing the vaccine knowing that if not properly stored the vaccine would be ineffective.”

The Moderna vials must be kept between 36 to 46 degrees Fahrenheit. They are effective for up to 12 hours once they are left out in room temperature, but useless afterwards.

Brandenburg on Thursday allegedly removed 57 vials containing approximately 570 doses of the coronavirus vaccine and then returned them to refrigerated storage on Christmas morning. A fellow employee discovered his plot however, and immediately notified superiors.

While health care workers disposed of most of the doses, Grafton police said they had reported 57 patients who received a vaccine that had been left out overnight. Bahr said the shot would either provide less protection or be completely ineffective.