This is 42-year-old nurse, Daniela Poggiali, suspected by police of killing one of her patients at a hospital in northern Italy.

Now prosecutors are looking into the suspicious deaths of 37 others at Lugo's Umberto 1 hospital.

Residents say they're appalled at the allegations.

(SOUNDBITE) (Italian) ELDERLY MAN NANDO SCARPELLI SAYING:

"I am so sorry for what has happened. I just can't put my feelings into words."

(SOUNDBITE) (Italian) LUGO RESIDENT LORELLA GUIDOBONI SAYING:

"I think there should have been more controls by the ward sisters."

Police allege the patients received injections of potassium, which can cause the heart to stop and is difficult to trace.

Poggiali has denied all accusations, saying says she's a victim of a plot against her.