 In addition, one or two Supervisors will oversee the First Contact process (see above), ensuring calls are dealt with correctly.The role of Supervisor is filled either by a Sergeant or by an experienced member of the civilian staff.Supervisors are commonly (but incorrectly) referred to as "Controllers"; the post of Controller was a historic post prior to the introduction of the C3i programme, and was responsible for the supervision and staff welfare of CAD Operators on a particular borough.