(dissenting). The principal issue in this case is the proper construction of General Statutes § 53a-54c which requires the state to prove that someone charged with a felony murder “in the course of and in furtherance of such crime or flight therefrom . . . cause[d] the death of a person . . . .” Because I disagree with the majority’s construction of this statutory language, I must dissent from the affirmance of the defendant’s conviction.
The majority opinion concludes that the phrase “in furtherance of” in § 53a-54c means proximate cause, or less. The primary purpose of the statutory language, according to the majority, is to limit the vicarious liability of a principal when an accomplice commits a homicidal act beyond the scope of the contemplated underlying felony. For cases involving vicarious criminal liability, the phrase “in furtherance of” thus imposes the requirement of a relationship beyond that of mere causation in fact, a requirement analogous to that of proximate cause in the law of torts. This requirement was adequately communicated to the jury, in the view of the majority, by the trial court’s equation, in its instructions, of “in furtherance of’ with “in the natural progression of.” For cases not involving vicarious criminal liability, however, when the underlying felony is the crime of arson, the majority relies upon *655the construction of a similar statute by New York courts, which have held the phrase “in furtherance of” to be “meaningless and at best surplusage.” People v. Lozano, 107 Misc. 2d 345, 349, 434 N.Y.S.2d 588 (1980). Because the present criminal proceedings arose out of a charge of direct liability for a death that occurred in the course of and in furtherance of the crime of arson, the majority necessarily holds that the “in furtherance” requirement is meaningless in this case.
For three separate but related reasons, I disagree with the majority’s construction of the language of “in furtherance of” in § 53a-54c. First, I would adhere to the general proposition that, in the construction of criminal statutes, we are obligated to prefer an interpretation of statutory language that gives independent meaning to each and every condition on criminal liability that the legislature has chosen to impose. Second, in the construction of this particular statute, I would give greater weight to inferences to be drawn from recent case law in this court than to contrary interpretations of similar legislation in neighboring jurisdictions. Third, I would attach confirmatory significance to the intervening action of the legislature which took pains, in creating a new crime of arson murder, to excise the “in furtherance of” requirement that previously, as in the present proceedings, had accompanied all charges of felony murder. Applying these principles to this case, I cannot agree that “in furtherance of” is meaningless surplusage in § 53a-54c.
Well established rules of statutory construction warn against expansive reading of penal statutes. “A criminal statute must be strictly construed, and no act should be held to be within its ambit which does not fall within its spirit and the fair ambit of its language .... The meaning of the statute cannot be extended by presumption or intendment .... No part of the statute is to *656be treated as insignificant or unnecessary, and there is a presumption of purpose behind every sentence, clause or phrase .... It is the expressed intent of the legislature which controls . . . and that intent is to be found in the meaning of what it says .... The words used are to be given the commonly approved usage of the language.” (Citations omitted.) State v. Moore, 158 Conn. 461, 465, 262 A.2d 166 (1969). In State v. Grant, 176 Conn. 17, 20, 404 A.2d 873 (1978), we reiterated that, in construing a criminal statute, this court treats no part of a legislative enactment as insignificant and unnecessary, but endeavors to harmonize the entire statute, so that “each part [may be] made operative.” Since § 53a-54c in terms requires the state to prove that death has been caused “in the course of and in furtherance of” (emphasis added) the underlying crime, we must endeavor to give independent meaning to each of the elements of the crime with which the defendant has been charged.
There is no apparent disagreement that “in the course of” in § 53a-54c requires the state to show a temporal connection between the death and the underlying felony, and that such proof was introduced in this case. What divides us is a fair meaning, a commonly approved usage for “in furtherance of” as an independent element of felony murder. In approaching this question, I believe that the majority does not give adequate weight to our recent decision in State v. MacFarlane, 188 Conn. 542, 450 A.2d 374 (1982).
In State v. MacFarlane, the defendant appealed from a conviction of felony murder that occurred in the course of the commission of a burglary. The state charged that the defendant or his friend had killed the victim when she awoke as they were burglarizing her home. State v. MacFarlane, supra, 543. The defendant’s appeal raised a number of claims of error *657unrelated to the present case, but in his third claim the defendant argued that the trial court had erred “in not defining ‘in furtherance of [burglary]’ as an element of felony murder, and in not including that phrase in its summary to the jury of the felony murder elements.” Id., 550-51. In finding no error, we held that “the phrase ‘in furtherance of’ could properly be considered by the jury in its ordinary meaning.” Id., 551-52. In response to the defendant’s fourth claim of error, that burglary was not a crime against a person, was unlikely to result in death, and was therefore an inappropriate precondition for a charge of felony murder, we went on to explain “the rationale behind the elements that the death must be caused ‘in the course of and in furtherance of’ the burglary.” Id., 552. That rationale can be found, we stated, as it had been found for a predecessor felony murder statute, by noting that “ ‘crimes against the person like robbery, rape, common law arson and burglary are, in common experience, likely to involve danger to life in the event of resistance by the victim or the attempt of the perpetrator to make good his escape and conceal his identity.’ . . . State v. Rossi, 132 Conn. 39, 44, 42 A.2d 354 (1945), overruled in part on other grounds, State v. Tomassi, 137 Conn. 113, 123, 75 A.2d 67 (1950).” (Emphasis omitted.) Id., 553. Accordingly, we found no error in the trial court’s instructions relating burglary to felony murder.
State v. MacFarlane is instructive on several counts. It assigns significance to “in furtherance” by holding that this language is to be given its “ordinary meaning.” It describes “in the course of and in furtherance of” as elements, in the plural, of felony murder. It suggests a plausible content for the “ordinary meaning” of “in furtherance of” in the common experience that some crimes, including arson and burglary, are likely *658to result-in death because of resistance by the victim or the attempt of the perpetrator to escape undetected from the scene of the crime. While this gloss on the felony murder statute compelled affirmance of MacFarlane’s conviction, it seems to me to compel acquittal of this defendant. The tragic death of the victim in this case did not occur in circumstances that were, in any ordinary sense, “in furtherance of” the crime of arson.
I do not understand how the majority can dismiss State v. MacFarlane as inapposite to the present appeal. As I read MacFarlane, the opinion directly addressed the meaning of “in furtherance of” in § 53a-54c. This is the felony murder statute under which MacFarlane was charged and convicted. Although the MacFarlane interpretation of § 53a-54c arose in the context of review of instructions to the jury, that procedural nexus does not, it seems to me, deprive its holding of precedential value. Because State v. MacFarlane is consistent with our mandate to assign significance, if we can, to each statutory element of a crime, I would follow its holding in preference to that of the New York trial court cases on which the majority relies.
Finally, I believe the majority does not sufficiently take account of revisions of the felony murder statute subsequent to the criminal proceedings in this case. In 1979, the legislature created a separate new crime of arson murder that has been codified as General Statutes § 53a-54d. Under this latter section, a defendant can now be found guilty of murder “when, acting either alone or with one or more other persons, he commits arson and, in the course of such arson, causes the death of a person.” Where the new statute applies, the state need no longer prove “in furtherance of.” We ordinarily presume, even in civil cases, that statutory changes *659reflect intentional modification of existing law. Heffernan v. Slapin, 182 Conn. 40, 49, 438 A.2d 1 (1980); Robinson v. Unemployment Security Board of Review, 181 Conn. 1, 21 n.6, 434 A.2d 293 (1980). The presumption strikes me as even more compelling in the amendment of penal statutes where the import of the amendment is to broaden the scope of criminal liability. Such an amendment cannot be justly characterized as merely construing or clarifying a prior penal statute. In my view, the 1979 action of the legislature clearly supports the argument of the defendant that the phrase “in furtherance of” in § 53a-54c should not be dismissed as meaningless surplusage.
I would find error in the defendant’s conviction of felony murder.1
The statutory problems that inhere in the defendant’s felony murder conviction in no way affect his conviction of arson in the first degree in violation of General Statutes § 53a-111 (a) (1) and (2). I agree that there is no error with regard to the arson conviction.