(a) An investigation by the department or a state agency shall include an interview with the elderly person or person with a disability, if appropriate, and with persons thought to have knowledge of the circumstances. If the elderly person or person with a disability refuses to be interviewed or cannot be interviewed because of a physical or mental impairment, the department shall continue the investigation by interviewing other persons thought to have knowledge relevant to the investigation.
(b) The investigation may include an interview with an alleged juvenile perpetrator of the alleged abuse, neglect, or exploitation.
(c) The department or state agency may conduct an interview under this section in private or may include any person the department or agency determines is necessary.