Massachusetts Superior Court Rule 55:
Experts in Criminal and Delinquent Children Cases
The court will not allow compensation as an expert witness to a salaried medical examiner or a salaried physician of a penal institution or place of detention, unless it appears by the certificate of the district attorney that he has testified as an expert.
The court will allow no fee to a salaried physician of a penal institution or place of detention for making an examination into the mental condition of a person held in custody therein or for a report or medical certificate as to such condition.
(Applicable to criminal cases and cases of delinquent children)