(dissenting, with whom Brown, J., joins). The substance of the plaintiff’s contention is that G. L. c. 127, § 83B,* 1 2must be read together with the fourth sentence of the first paragraph of G. L. c. 127, § 129, which authorizes the Commissioner to restore forfeited good conduct deductions “in the event of the prisoner’s subsequent good conduct.”2 From our examination of these provisions, and *430the legislative course of each of the statutes in which they are respectively contained, we conclude that the plaintiff is correct and that the judgment should be reversed.* *3
The prison camp escape provision, as it now reads (note 1, supra), was enacted in 1951 as part of a comprehensive program for the establishment of prison camps in State forests. St. 1951, c. 755, inserting §§ 83A-83D, inclusive, in chapter 127 of the General Laws.4 At that time § 129 (as rewritten by St. 1948, c. 450 — “An Act relative to deductions from maximum sentences of prisoners”) contained substantially the same provision for the administrative forfeiture of good conduct allowances as is presently in effect in that section, except that it made no provision for their restoration for subsequent good conduct (see note 2, supra). Section 129 also then provided that: “If during the term of *431imprisonment... such prisoner shall commit any offense of which he shall be convicted and sentenced, all deductions hereunder from the former sentence of imprisonment... shall be thereby forfeited” (herein referred to as the 1948 conviction forfeiture provision).
In 1955 the Legislature enacted a thoroughgoing reorganization of the penal system by St. 1955, c. 770, entitled “An Act relative to the penal and reformatory institutions of the commonwealth.” See 1955 Ann. Surv. of Mass. Law, §§ 12.1-12.13. It was based on a study of the entire correction system by a commission of penologists, headed by President Wessell of Tufts College. 1955 Sen. Doc. No. 750, “Report and Recommendations of the Governor’s Committee to Study the Massachusetts Correctional System.” The Wessell committee had been appointed soon after a four-day rebellion in Charlestown prison and was concerned with the problems of prison discipline. The study points out that good conduct allowances “are useful for institutional discipline, using the term discipline in the proper sense, that is, as an incentive to good morale, rather than in a negative sense, discipline maintained by punishment” (at 71), and further that “ [t]he granting or denial of good-time allowances is a matter of institutional management and discipline. It should be controlled within the Department of Correction...” (at 73). In accordance with this principle the Wessell committee recommended that the provision for automatic loss of good time upon conviction for an offense while in prison (the 1948 conviction forfeiture provision) be eliminated entirely; and this recommendation was embodied in the revised draft of § 129 of c. 127 submitted by the Wessell committee (see 1955 Sen. Doc. No. 750, at 142-143), in the draft of the Special Committee on the Reorganization of the Correctional System of the House of Representatives to which the Wessell report was referred (see 1955 House Doc. No. 3098, at 40-41), and in the ultimate legislation (St. 1955, c. 770, § 66), which rewrote § 129. The draft of the House committee bill and the ultimate legislation (though not the original draft of the Wessell committee bill) also added, to the provision in § 129 for the admin*432istrative forfeiture of good conduct deductions, a further provision for their restoration for “subsequent good conduct” (see note 2, supra). 1955 House Doc. No. 3098, at 41.
However, in spite of the elimination of the 1948 conviction forfeiture provision, both drafts and the ultimate legislation let stand the prison camp escape provision in § 83B (see note 1, supra). We do not view this as an inadvertance,5 and it need not be regarded as an inconsistency. The prison camp escape provision — unlike the 1948 conviction forfeiture provision for ministerial forfeiture because of prison offenses — did not require a conviction and sentence. (Contrast G. L. c. 127, § 83C, note 4, supra.) We note the characterization of the § 83B prison camp escape provision in the Attorney General’s brief (at 2) in Gregoire, petitioner, 355 Mass. 399 (1969), which dealt with the relationship between the prison camp escape provision and a 1963 provision (St. 1963, c. 535) with reference to convictions for offenses while in prison: — “Section 83B punishes escapes or attempted escapes as an infraction of rules whether or not a conviction is obtained, while section 129 punishes any act for which a conviction is secured...” (emphasis in original). See Commonwealth v. Sneed, 3 Mass. App. Ct. 33, 34 (1975), which deals with the situation in which “conviction of escape... follow [s] the imposition of a forfeiture of good time arising from the same occurrence,” which forfeiture is administrative in nature. See cases cited. Compare Munkley v. Hoyt, 179 Mass. 108, 111 (1901).
Nor are administrative proceedings to determine whether an escape has occurred necessarily perfunctory; they may *433require factual determinations of some complexity. See Commonwealth v. Gosselin, 1 Mass. App. Ct. 849 (1973), S.C. 365 Mass. 116 (1974). And at least since Wolff v. McDonnell, 418 U. S. 539, 557 (1974), such proceedings may also require the application of procedural safeguards comparable to those applicable to the administrative forfeiture provisions of § 129. See Commonwealth v. Druken, 356 Mass. 503, 506-509 (1969).
The application of the provision for administrative restoration of good time in § 129 to the good time administratively forfeited upon proceedings under § 83B seems to us to place the prison camp escape provision in the context of the Wessell committee’s recommendation for greater administrative flexibility in the administration of good time; and thus the failure by the Wessell committee to make any change in the § 83B provision becomes understandable. Indeed, when the 1948 conviction forfeiture provision was reinstated by St. 1959, c. 445 (see 1963 Ann. Surv. Mass. Law § 11.3), no change was made in the prison camp escape provision (note 1, supra). Nor was any change made in that provision in 1963 when St. 1963, c. 535, eliminated the conviction forfeiture provision and substituted for it a provision that the only entitlement lost would be from the new sentence — though the 1963 statute was based on the recommendations of the Department of Correction (1963 House Doc. Nos. 20,21), made together with recommendations for changes in good time allowances for inmates of prison camps. See 1963 House Doc. No. 22, which became G. L. c. 127, § 129C, by St. 1963, c. 164 (“An Act providing a further deduction of sentence for good conduct while confined át a prison camp”).
That the forfeited deductions which are subject to restoration are directed by § 83B, rather than by § 129, is not particularly significant. Indeed, additional good time allowances for prison camp inmates are provided in the separate provision of G. L. c. 127, § 129C; and it would surely be anomalous to hold that, because that provision was separate from the provisions of § 129, the administrative forfeiture and restoration provisions of § 129 have no application *434to these additional good time allowances. See Commonwealth v. Hayes, 372 Mass. 505, 508-512 (1977).
Accordingly, we view the “such deductions” which may be restored in § 129 as referring not only to those administratively forfeited in § 129, but also to those administratively forfeited in § 83B.
This comports with the teaching of Gregoire, petitioner, 355 Mass. at 400, that the statutes be read together as a harmonious system. See Lembersky v. Parole Bd. of the Dept. of Correction, 332 Mass. 290, 292-293 (1955) ; Wood v. Commissioner of Correction, 363 Mass. 79, 82, fn.5 (1973). It also comports with the more general rule that penal statutes be strictly construed in favor of a defendant. Wood v. Commissioner of Correction, 363 Mass. at 81, and cases cited.
General Laws c. 127, § 83B, as amended through St. 1972, c. 172, § 2, presently provides in pertinent part: “If a prisoner escapes or attempts to escape from a prison camp all deductions from the sentence he is then serving shall be thereby forfeited” (hereinafter referred to as the prison camp escape provision).
General Laws c. 127, § 129, as amended through St. 1967, c. 379, presently provides in pertinent part: “If a prisoner violates any rule of his place of confinement, the commissioner of correction..., upon the recommendation and evidence submitted to... [him] in writing by the principal officer, or officer in charge, shall decide what part, if any, *430of such good conduct deduction from sentence or sentences shall be forfeited by such violation [the § 129 administrative good time forfeiture provision], and may likewise determine, in the event of the prisoner’s subsequent good conduct, whether any or all of such deduction shall be restored [the § 129 good time restoration provision].” The good time forfeiture provision has been substantially unchanged since at least 1932. See G. L. (Ter. Ed.) c. 127, § 130.
The judgment entered in the Superior Court declared that the Commissioner “does not have discretion to restore ... earned good conduct deductions from a sentence which were forfeited under 5 83B ....” Following the entry of judgment the plaintiff filed a motion for a new trial, one ground of which was that certain “newly discovered evidence [a Department of Correction administrative memorandum and a “Commissioner’s Bulletin”] demonstrates clearly that escape from a prison camp is ... violative of an express rule of the institution.” The judge accepted the plaintiff’s interpretation of the proffered documents and assumed, without deciding, that they “were in force and effect”; nevertheless he denied the motion as a matter of law on the ground that under G. L. c. 127, § 129, “the commissioner may not restore good conduct credits which the legislature has mandated to be forfeited under section 83B.” The plaintiff’s appeals are from the judgment and from the denial of his motion for a new trial.
Section 83C (as so inserted), of which the defendant was convicted, provides: “A prisoner who escapes or attempts to escape from any prison camp or from land adjacent thereto or from the custody of the officer thereof or while being conveyed to and from any such camp may be pursued and recaptured and shall be punished by imprisonment in the state prison for not more than ten years or by imprisonment in a jail or house of correction for not more than two and one half years.”
The Wessell committee and the House committee were both well aware of the prison camps. The Wessell committee urged the expansion of the prison camp program to include more units (1955 Sen. Doc. No. 750, at 32), and the ultimate legislation (St. 1955, c. 770, § 120) directed the establishment of three additional camps. The House committee bill specifically deleted from § 83B a provision for work time allowance which the Wessell committee had recommended be eliminated as unsound (1955 Sen. Doc. No. 750, at 73) but which its draft had only eliminated from § 129 and not from § 83B. See 1955 House Doc. No. 3098, at 32; 1955 Sen. Doc. No. 750, at 142 and 136; Gildea v. Commissioner of Correction, 336 Mass. 48, 50-51 (1957).