A Tisbury police sergeant has been dismissed following a disciplinary proceeding with the town selectmen over performance in the line of duty during a domestic assault incident this summer.

Sgt. Robert Fiske had been on paid administrative leave since August pending the result of an internal investigation. Sergeant Fiske was the officer in charge on July 23 when police responded to a call for a domestic assault involving a husband and wife on Spring street.

After they arrived at the scene, police transported the woman to the Martha’s Vineyard Hospital for treatment; her husband had left the house and was not at the scene. While police searched for the husband they left a 15-year-old female at home alone with three children. The man subsequently returned and allegedly raped and assaulted the young female, police said. David Thrift, 30, was later arrested and charged in the case. Mr. Thrift was indicted by a Dukes County grand jury this fall and is awaiting trial in superior court on 10 charges, including rape of a child and assault with a dangerous weapon.

Tisbury selectmen last week held a lengthy executive session to consider the disciplinary proceedings against Sergeant Fiske, a 16-year veteran of the force. Following the session, Mr. Fiske was terminated. Tisbury town officials confirmed the termination yesterday could not comment further on advice of town counsel.