N.J. Stat. § 26:6-50
Any physician licensed to practice medicine and surgery in this State may conduct a post-mortem and necroscopic examination upon the body of a deceased person if he first obtains the consent in writing of any of the following persons who shall have assumed responsibility and custody of the body for purposes of the burial: surviving spouse, domestic partner as defined in section 3 of P.L. 2003, c. 246(C.26:8A-3), adult child, parent, or other next of kin, of the deceased person. In the absence of any of the foregoing named persons any other person charged by law with and who shall have assumed responsibility and custody of the body for the burial may give such consent. Where 2 or more of the abovementioned have assumed such responsibility and custody of the body for purposes of burial, the consent of 1 of such persons shall be sufficient.
N.J.S. § 26:6-50