An Italian nurse has been accused of killing up to 38 of her patients because she found them or their families annoying.
Daniela Poggiali (42) was initially arrested over the unexpected death of an elderly patient, according to local reports.
Although Rosa Calderoni had been admitted for a routine illness, a post-mortem examination found high levels of potassium in her bloodstream.
The investigation into Poggiali, from Lugo in the northeast of Italy, soon widened - and police are now reviewing 37 other cases, with 10 of those described as "very suspicious".
Ms Poggiali denied wrongdoing when questioned by prosecutors - and maintained she was the victim of a conspiracy orchestrated by her enemies, according to the ANSA news agency.
Prosecutor Alessandro Mancini told Il Resto Del Carlino, an Italian newspaper, that there are "insurmountable difficulties" with their murder investigation as a lot of time has passed since some of the deaths.
Another prosecutor on the case, Rossella Materia, claimed the suspect is a sadist "who draws pleasure in provoking the death of the patients in her care".
Since Ms Poggiali's arrest, her colleagues have described her as a "cold person who was always eager to work".
One co-worker has made further allegations about the nurse, claiming that she once gave strong laxatives to patients as her shift ended make work more difficult for the nurses taking over.
