My 96-year-old Mother Is Appearing More Paranoid By The Day....all

My 96-year-old mother is appearing more paranoid by the day....all kind of people are stealing all kinds of things from her. Mom lives in a long-term care facility. A nurse practitioner suggested to me that that sort of paranoia is a common symptom of dementia. If this is true, please steer me toward some studies/articles that deal with this. Thank you.