Massachusetts Guide to Evidence 2025 Edition MA R EVID § 1117

(1) the respondent is mentally ill;

(2) by reason of that illness, the failure to commit or retain the respondent in a facility would create a likelihood of serious harm to the respondent or another; and

(3) if the respondent is already committed to a mental health facility or to Bridgewater State Hospital, discharge of the patient from said facility is imminent.

(1) the expert witness testimony will assist the trier of fact;

(2) the witness is qualified as an expert in the relevant area of inquiry;

(3) the facts or data in the record are sufficient to enable the witness to give an opinion that is not merely speculation;

(4) the expert opinion is based on a body of knowledge, a principle, or a method that is reliable; and

(5) the expert has applied the body of knowledge, the principle, or the method in a reliable manner to the particular facts of the case.

(1) facts observed by the witness or otherwise in the witness's direct personal knowledge;

(2) evidence already in the record or that will be presented during the course of the proceedings, which facts may be assumed to be true in questions put to the witness; and

(3) facts or data not in evidence if the facts or data are independently admissible in evidence and are a permissible basis for an expert to consider in formulating an opinion.

(1) The privilege does not apply to a disclosure made by a psychotherapist or social worker who, in the course of diagnosis or treatment of the patient, determines that the patient is in need of treatment in a hospital for mental or emotional illness or presents an imminent threat of dangerous activity, and who, on the basis of that determination, discloses such communication for the purpose of either placing or retaining the patient in such hospital, provided, however, that the provisions of this section shall continue in effect after the patient is in that hospital, or after placing the patient under arrest or under the supervision of law enforcement authorities.

(2) Whenever a psychiatrist, psychologist, or social worker interviews a patient on behalf of the Commonwealth with the purpose of preparing for a hearing, whether or not the interview was ordered by the court, the patient must be warned before the interview begins that everything said during the interview is not subject to privilege and may be presented against the patient in the hearing.

(1) evidence of the necessity of such services or treatments;

(2) the diagnosis, prognosis, or opinion as to the proximate cause of the condition so diagnosed; or

(3) the opinion as to disability or incapacity, if any, proximately resulting from the condition so diagnosed.