A capacity assessor is someone who has special training and has been approved by the government to decide if people are mentally incapable. This can be a doctor, nurse, psychologist, occupational therapist, or social worker. They assess a person's mental capacity and decide if the person is able to make decisions about their property, personal care, or both.
You must pay for the assessment. The fee usually depends on things like the person’s profession and expertise. The Office of the Public Guardian and Trustee has a list of capacity assessors in Ontario.