N.J. Stat. Ann. § 2A:158A-9

To achieve a proper balance between the services to be provided pursuant to this act and the efficiency of the operation as a whole, as well as to stimulate the continual development of professional experience and interest in the administration of criminal justice, the Public Defender shall divide the case workload of the office between the professional staff and the trial pool or pools. In any case where the matter involved requires some special experience or skill not available on the professional staff, the Public Defender shall engage counsel on a case basis, and shall assign a suitable member of the staff to the extent feasible to assist counsel so engaged. Counsel shall also be engaged on a case basis whenever needed to meet case load demands, or to provide independent counsel to multiple defendants whose interests may be in conflict.