New Jersey Statutes Title 53. State Police 53 § 4-1

Whenever the department of state police desires to examine a member of the department in relation to the discharge of his official duties or conduct, or concerning the possession or disposition by him in his official capacity of any property belonging to the department, or to inspect or examine any book account, voucher or document in the possession or under control of a member of the department as such member, relating to the affairs or interests of the department, the superintendent or deputy superintendent of state police may issue a subpoena ad testificandum or subpoena duces tecum to any person to appear before him and give testimony or information required for the purpose above mentioned. Such subpoenas may be served by any police officer of the municipality wherein the person to be subpoenaed resides, or by a member of the state police.