concurring.
¶ 45 I respectfully differ from the majority’s analysis of Arizona’s first-degree (premeditated) murder1 statute.2 Therefore, I can only concur in the result.
*284¶ 46 A person commits murder in the first degree if, “[intending or knowing that [his] conduct will cause death, [he] causes the death of another with premeditation,” Ariz. Rev.Stat. (“A.R.S.”) § 13-1105(A)(1), and it is with the meaning of the word “premeditation” that we now struggle. Between 1978 and 1998, the statutory definition of “premeditation” was the following:
[T]he defendant acts with either the intention or the knowledge that he will kill another human being, when such intention or knowledge precedes the killing by any length of time to permit reflection, but an act is not done with premeditation if it is the instant effect of a sudden quarrel or heat of passion.
A.R.S. § 13-1101(l)(1978)(emphasis added). In 1997, another panel of this court held that this definition of “premeditation” required not only time to allow “reflection” but proof that actual reflection had occurred during this time. State v. Ramirez, 190 Ariz. 65, 69, 945 P.2d 376, 380 (App.1997). In apparent response, the 1998 legislature amended the definition of “premeditation” to state the following:
‘Premeditation ’ means that the defendant acts with either the intention or the knowledge that he will kill another human being, when such intention or knowledge precedes the killing by any length of time to permit reflection. Proof of actual reflection is not required, but an act is not done with premeditation if it is the instant effect of a sudden quarrel or heat of passion.
A.R.S. § 13-1101(1)(1998) (emphasis added). Comparing the two statutory definitions, the legislature did not change the phrase upon which the majority focuses, “such intention or knowledge precedes the killing by any length of time to permit reflection,” it added the critical sentence yet the one ignored by the majority: “Proof of actual reflection is not required.”
¶47 In both versions of the statute, the language defining premeditation says that the defendant’s intent and knowledge must precede the murder by a length of time sufficient to permit reflection. Thus, “premeditation” is a period of time during which the mind actually considers the performance of an act, the formation of an intention or determination to kill, which results in the death of another.
¶ 48 While reflection may be suggested by the passage of time, premeditation relates to mental processes not necessarily readily susceptible to “proof of actual reflection.” There may be no diary entries, documentation or other expression of the contemplated murder. There may not be overt “planning activity” or facts regarding the defendant’s behavior prior to the killing which might indicate his design to take a person’s life or facts about the defendant’s previous behavior to suggest the contemplation of the victim’s death, but there nonetheless might be evidence regarding the nature or manner of the death sufficient to demonstrate an intent to kill according to a preconceived design. See, e.g., State v. Murray, 184 Ariz. 9, 32, 906 P.2d 542, 565 (1995)(holding that shooting victims “execution-style” shows that defendants had sufficient time to permit reflection), cert. denied, 518 U.S. 1010, 116 S.Ct. 2535, 135 L.Ed.2d 1057 (1996). It was in seeming response to this reality ignored in the Ramirez opinion that the legislature acted. And it is in this context that the statutory phrase “proof of actual reflection is not required” can be fairly interpreted' as not requiring specific proof of a “period of time” preceding the killing but, rather, leaving the jury free to draw from the totality of the evidence a reasonable inference as to the (lack of) spontaneity or adequacy of the defendant’s reflection. The emphasis is on the *285jury’s resolution that a length of time sufficient to “permit reflection” preceding the murder occurred such as to warrant a legitimate inference that premeditation occurred. This is not dissimilar to asking jurors to determine whether an individual acted “reasonably” or to resolve other conflicts similarly elusive but dependent upon the human experience.
¶ 49 The addition of the phrase “proof of actual reflection is not required” does not diminish the concept that premeditation is a design, a determination to kill, distinctly formed in the mind at any moment “preced[ing] the killing by any length of time [sufficient] to permit reflection,” certainly as distinguished from “the instant effect of a sudden quarrel or heat of passion.” A.R.S. § 13-1101(1). Because it may be as alacritous as successive thoughts of the mind, State v. Greene, 192 Ariz. 431, 446 ¶ 72, 967 P.2d 106, 121 (1998); see also State v. Hutton, 143 Ariz. 386, 389, 694 P.2d 216, 219 (1985) (“This length of time [to permit reflection] may be as instantaneous as the time it takes to make successive thoughts to kill ....), there may be no palpable “proof of actual reflection.” Indeed, “proof of actual reflection” may be as difficult of identification as that of any other thought because, if the jury believes from the evidence that the act constituting the killing has been preceded by and has been the result of premeditation, no matter how rapidly the act follows the thought, it is premeditated. For this reason, the law neither does nor can undertake to insist on proof of the actual period during which the thought must be pondered before it can ripen into “the intention or the knowledge that he will kill another human being” such that it is premeditated. This will vary with different individuals and under varying circumstances. The true test is not the duration of time but, rather, the extent of the reflection. A cold, calculated judgment and decision to kill may be reached in the most brief period of time, but it is enough if there is time for the mind to think upon or consider the act and then determine to do it. If, therefore, the killing is not the instant effect of impulse — if there is hesitation or doubt to be overcome, a choice made as the result of thought or reflection, however short the struggle between the intention and the act— it is sufficient to characterize the crime as premeditated murder.
. First-degree murder also encompasses murder committed in the course of a given felony. This *284opinion pertains only to that manner of first-degree murder involving premeditation.
. I add what is probably an unnecessary reminder that it is this court's duty to uphold the constitutionality of a statute whenever possible. Arizona Dep't of Public Safety v. Superior Court (Falcone), 190 Ariz. 490, 494, 949 P.2d 983, 988 (App.1997); Almendarez-Torres v. United States, 523 U.S. 224, 237, 118 S.Ct. 1219, 140 L.Ed.2d 350 (1998) ("As Justice Holmes said long ago: 'A statute must be construed, if fairly possible, so as to avoid not only the conclusion that it is unconstitutional but also grave doubts upon that score,’ ” quoting United States v. Jin Fuey Moy, 241 U.S. 394, 401, 36 S.Ct. 658, 60 L.Ed. 1061 (1916).).