N.J. Stat. § 43:10-24
Physical unfitness or incapacity for further duty of any county detective shall, for all purposes of this article, be established and determined by a board of three physicians who shall be designated for that purpose, as follows: One by the prosecutor of the pleas of the county, one by the county detectives of such county or a majority of them, and one by the county treasurer of such county. The three physicians so designated shall examine the county detective applying for retirement upon one-half pay because of physical unfitness or incapacity for further duty, and if they or a majority of them, find him physically unfit or 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 county treasurer, and thereupon the applicant shall be retired upon one-half pay.
N.J.S. § 43:10-24