N.J. Stat. § 43:10-51
Permanent incapacity for further duty of any county probation officer shall, for all purposes of this article, be established and determined by a board of three physicians, who shall be designated for that purpose by the assignment judge of the Superior Court in such county. The three physicians so designated shall examine such county probation officer and if they, or a majority of them, find that such county probation officer is permanently incapacitated for further duty, they or a majority of them, shall make and sign a certificate to that effect and file the same with the assignment judge of the Superior Court, the chief probation officer and the county treasurer, and thereupon the applicant shall be retired upon one-half pay.
N.J.S. § 43:10-51