Does it say how often the witnesses who found her behaviour suspicious, suspected her of being involved, caught her in the act, etc. reported her to colleagues, hospital authorities, the police? Or what ultimately prompted her arrest?
If she was reported multiple times, independent of each other and before any investigation had begun then that would be pretty solid. If it never happened and all this came out during the investigation, perhaps after her name was out there as a suspect, then that doesn't look quite as strong.