with whom Mr. Justice Marshall joins, concurring.
I join the Court’s opinion affirming the judgment in this case, despite my reservations that the decision of the Superior Court of New Jersey, Appellate Division, 151 N. J. Super. 200, 376 A. 2d 950 (1977), certification denied, 75 N. J. 597, 384 A. 2d 827 (1978), may well rest on independent and adequate state grounds.
The privilege against self-incrimination is not set out in the New Jersey Constitution. Its origins are instead to be found in the common law, see State v. Fary, 19 N. J. 431, 434-435, 117 A. 2d 499, 501-502 (1955), and in statutes. See N. J. Stat. Ann. § 2A:84A-19 (West 1976). Although New Jersey courts have looked to constructions of the Fifth Amendment of the Federal Constitution as a source of illumination for the interpretation of the state privilege, see In re Pillo, 11 N. J. 8, 15-17, 93 A. 2d 176, 179-180 (1952), they have also held that the interpretation of that privilege is “a matter of state law and policy, as to which [New Jersey] may impose standards more strict than required by the federal Constitution, which standards will control regardless of the final outcome of the question in the federal sphere.” State v. Deatore, 70 N. J. 100, 112, 358 A. 2d 163, .170 (1976). Cf. State v. Johnson, 68 N. J. 349, 353, 346 A. 2d 66, 67-68 (1975).
In this context the Appellate Division’s decision appears *461to rest on the independent and adequate state ground of N. J. Stat. Ann. § 2A:81-17.2a2 (West 1976). The Division's opinion begins by reciting the statute in toto, labeling it as “[t]he statutory authority for the State’s grant of immunity to defendant.” 151 N. J. Super., at 204, 376 A. 2d, at 952. The opinion states that “[t]he question is whether the State should be required to honor its promise, expressed in its statute . . ., not to use the testimony compelled in any subsequent criminal proceeding against the defendant . . . .” (Emphasis supplied.) Id., at 207, 376 A. 2d, at 954. Under these circumstances the Appellate Division’s references to decisions interpreting federal constitutional law seem to be mere analogies, illuminating the Division’s ultimate construction of N. J. Stat. Ann. § 2A:81-17.2a2.1 Logically, interpretations of the Fifth Amendment can at most serve as guidance to New Jersey’s interpretation of its own statute.2 It is also of no little significance that, although the State rests its case heavily on Harris v. New York, 401 U. S. 222 (1971), see Brief for Petitioner 38-39, the Supreme Court of New Jersey has recently held that the state privilege against self-incrimination may well be “stricter” than that required by Harris. See State v. Deatore, supra, at 116, 358 A. 2d, at 172.
But the Court reads the New Jersey court’s opinion as resting on the Federal Constitution. That reading would not have been possible had the New Jersey court’s opinion in this case been as explicit as in Deatore.3 However, since I fully agree *462with the Court’s disposition of the federal constitutional question, I shall not further press the point but join the Court’s opinion.
The immunity statute at issue in this case, N. J. Stat. Ann. §2A:81-17.2a2 (West 1976), is “self-executing,” State v. Vinegra, 134 N. J. Super. 432, 440, 341 A. 2d 673, 677 (1975), and therefore, as one New Jersey court put it, a “defendant's Fifth Amendment protection is derived from the statute.” Id., at 439, 341 A. 2d, at 677.
There is no suggestion, of course, that New Jersey’s interpretation of its statute violates the guarantees of the Fifth Amendment of the Federal Constitution.
“We reach that conclusion as a matter of state law and policy . . . *462regardless of the final outcome of the question in the federal sphere.” 70 N. J., at 112, 358 A. 2d, at 170.