A nurse was arrested in Italy over the weekend for allegedly killing close to 40 patients because either they, or their family members, got on her nerves.

The New York Post reports that police began investigating 42-year-old Daniela Poggiali after a patient, 78-year-old Rosa Calderoni​, died from a potassium injection:

Calderoni had been admitted to the hospital with a routine illness before she died unexpectedly. Tests showed she died with a high amount of potassium, which can provoke cardiac arrest, in her bloodstream, according to the Central European News.

After looking into Calderoni's death, authorities learned that another 38 happened under mysterious circumstances while Poggiali was on duty. While reviewing Poggiali's phone, authorities found a shocking picture of her giving the thumbs up next to the body of a patient who had jus died.

Prosecutor told the Corriere di Bologna that in his years of seeing startling images, "there were few [as shocking]" as what was found on Poggiali's phone.

[via New York Post and Corriere di Bologna]