SELYA, Circuit Judge.
This appeal raises interesting questions about the contours of 42 U.S.C. § 1983 (1988) and the reach of the Supreme Court’s core holding in DeShaney v. Winnebago County Social Servs. Dep’t, 489 U.S. 189, 109 S.Ct. 998, 103 L.Ed.2d 249 (1989). Concluding, as we do, that the court below appropriately applied DeShaney, we affirm the entry of summary judgment in the defendants’ favor.
I. BACKGROUND
Consistent with the method of Fed. R.Civ.P. 56, we canvass the material facts in a light that flatters, but does not impermissi-bly distort, the plaintiffs claims. We then recount the travel of the ease.
A. The Facts.
We outline the facts, omitting the graphic details on which our dissenting brother prefers to dwell. In our view, these details are not relevant to the legal issues posed on appeal.
In the early morning hours of May 26, 1988, plaintiff-appellant Wilfredo Martinez Rodriguez (Martinez), a youthful member of Puerto Rico’s police force, drove to the Loiza Street Precinct, located in the San Juan metropolitan area. Though Martinez was not scheduled to begin his shift until 4:00 a.m., he arrived early, pursuant to local custom, in order to procure his post assignment. Martinez alleges that he was on duty from the moment he arrived — even before his shift began — because from that point forward he was subject to the shift commander’s orders.
Upon Martinez’ arrival, a fellow officer who was on duty at the time, Angel Valentin Corali (Valentin), approached Martinez’ car and called him “pretty boy” (“papito lindo”). When Martinez alighted, Valentin drew his service revolver, pointed it at Martinez’ stomach, cocked the hammer, placed his finger on the trigger, and inquired if Martinez was afraid. Valentin then disarmed the weapon, and Martinez hurried inside the station, first telling Valentin: “Don’t horse around with that because you will kill me.”
Shortly after this fracas had occurred, Valentin accosted Martinez in the radio room, inserted his finger into a small hole in Martinez’ undershirt, and ripped it. Once again, Martinez walked away from Valentin. He then changed into his uniform, entered the waiting room, and reported to his shift supervisor, defendant-appellee Juan Trinidad Mar-rero (Trinidad).
Soon thereafter, Valentin reappeared, pointed his revolver at Martinez’ genitals, cocked the hammer, and, with his finger on the trigger, threatened to “blow away” Martinez’ penis (asking him, somewhat rhetorically, if he was scared). When Valentin lowered the weapon, Martinez immediately moved away from him. Within minutes Valentin again approached Martinez, cocked the revolver, aimed it at Martinez’ groin, and resumed his taunting. The revolver accidentally discharged, maiming Martinez.
The first encounter took place in the precinct’s parking lot and the rest transpired [983]*983inside the police station. According to Martinez, roughly twenty minutes elapsed from start to finish. All parties agree that the shooting, which occurred before the 4:00 a.m. shift change, was unintentional.1
B. Travel of the Case.
On May 22, 1989, Martinez filed suit in federal district court against numerous defendants, including, as relevant here, Rafael Colon Pizarro (Colon), Luis A. Velez Rentas (Velez), and Trinidad (collectively, “the officers” or “the defendants”).2 Invoking 42 U.S.C. § 1983 and premising jurisdiction on the existence of a federal question, see 28 U.S.C. § 1331 (1988), he alleged that his rights had been abridged in that each defendant owed him a duty to intervene and protect him from readily discernible harm at the hands of a fellow officer, but each defendant breached this duty by subsequent inaction.3 Martinez asserted pendent tort claims with respect to all three defendants and, with respect to Trinidad, asserted a section 1983 claim based on supervisory liability.
After a flurry of pretrial discovery, the officers moved for summary judgment. They argued, inter alia, that Valentin was not acting under color of state law when the mishap occurred; and that, therefore, onlooker officers did not have a constitutional duty to intervene on Martinez’ behalf. The district court referred the motions and Martinez’ timely opposition to a magistrate judge. The magistrate concluded that, under DeShaney, the officers had no constitutional obligation to protect Martinez from Valentin’s actions, and urged the district court to grant summary judgment. The plaintiff objected to the magistrate’s report and recommendation, but the district court, affording de novo review, see Fed.R.Civ.P. 72(b), adopted the report, accepted the recommendation, and entered judgment accordingly. This appeal followed.
II. THE SUMMARY JUDGMENT STANDARD
A district court may grant summary judgment only “if the plehdings, depositions, answers to interrogatories, and admissions on file, together with the affidavits, if any, show that there is no’ genuine issue as to any material fact and that the moving party is entitled to a judgment as a matter of law.” Fed.R.Civ.P. 56(c). We have charted the boundaries of this rule in case after ease, see, e.g., Coyne v. Taber Partners I, 53 F.3d 454, 457 (1st Cir.1995); National Amusements, Inc. v. Town of Dedham, 43 F.3d 731, 735 (1st Cir.1995), cert. denied, — U.S. —, 115 S.Ct. 2247, 132 L.Ed.2d 255 (1995); Vasapolli v. Rostoff, 39 F.3d 27, 32 (1st Cir.1994); Dow v. United Bhd. of Carpenters, 1 F.3d 56, 58 (1st Cir.1993); Pagano v. Frank, 983 F.2d 343, 347 (1st Cir.1993); Wynne v. Tufts Univ. Sch. of Med., 976 F.2d 791, 793-94 (1st Cir.1992), cert. denied, — U.S. —, 113 S.Ct. 1845, 123 L.Ed.2d 470 (1993); United States v. One Parcel of Real Property (Great Harbor Neck, New Shoreham, R.I.), 960 F.2d 200, 204 (1st Cir.1992); Rivera-Muriente v. Agosto-Alicea, 959 F.2d 349, 351-52 (1st Cir.1992); Medina-Munoz v. R.J. Reynolds Tobacco Co., 896 F.2d 5, 7-8 (1st Cir.1990); Garside v. Oseo Drug, Inc., 895 F.2d 46, 48-49 (1st Cir.1990); Brennan v. Hendrigan, 888 F.2d 189, 191-92 (1st Cir.1989), and it would serve no useful purpose to draw that map anew.
For present purposes, we need say no more than that summary judgment will lie if the record, even when taken in the aspect most favorable to the nonmovant, see Rivera-Muriente, 959 F.2d at 352, fails to yield [984]*984a trialworthy issue as to some material fact. In applying this principle, it is important to bear in mind that not every genuine factual conflict necessitates a trial. It is only when a disputed fact has the potential to change the outcome of the suit under the governing law if found favorably to the nonmovant that the materiality hurdle is cleared. See One Parcel, 960 F.2d at 204. Here, the record reflects a veritable salmagundi of bitterly disputed facts — but none that is material.
To that extent, then, our task is simplified. Exercising de novo review, see Pagano, 983 F.2d at 347, and adopting the plaintiffs version of all controverted facts (but not, however, giving credence to “eonelusory allegations, improbable inferences, [or] unsupported speculation,” Medina-Munoz, 896 F.2d at 8), we conclude that the court below did not err in jettisoning the section 1983 claims.
III. ANALYSIS
There are two essential elements of an action under section 1983: “(i) that the conduct complained of has been committed under color of state law, and (ii) that this conduct worked a denial of rights secured by the Constitution or laws of the United States.” Chongris v. Board of Appeals, 811 F.2d 36, 40 (1st Cir.), cert. denied, 483 U.S. 1021, 107 S.Ct. 3266, 97 L.Ed.2d 765 (1987); accord West v. Atkins, 487 U.S. 42, 48, 108 S.Ct. 2250, 2254, 101 L.Ed.2d 40 (1988); Daniels v. Williams, 474 U.S. 327, 330-31, 106 S.Ct. 662, 664-65, 88 L.Ed.2d 662 (1986). Of course, the reference to “state law” cannot be taken literally, for Puerto Rico enjoys the functional equivalent of statehood in regard to section 1983 and, thus, state law includes Puerto Rico law. See Playboy Enters., Inc. v. Public Serv. Comm’n of P.R., 906 F.2d 25, 31 n. 8 (1st Cir.), cert. denied, 498 U.S. 959, 111 S.Ct. 388, 112 L.Ed.2d 399 (1990); Berrios v. Inter Am. Univ., 535 F.2d 1330, 1331 n. 3 (1st Cir.), appeal dismissed, 426 U.S. 942, 96 S.Ct. 2665, 49 L.Ed.2d 1180 (1976).
For purposes of this appeal, the defendants do not contest the plaintiffs allegation that, at all relevant times, the defendants were on duty and acting under color of state law. This concession reduces our inquiry to whether the facts, taken most congenially to the plaintiff, can support a finding that the defendants violated a right secured to the plaintiff either by the Constitution or by federal law. Since the plaintiff has not alleged the transgression of any right secured to him under a federal statute, we may narrow the inquiry still further, limiting it to whether the facts show a violation of a constitutional right. It is to this elusive question that we next proceed.
A. The Duty to Intervene.
Plaintiff pins his hopes principally on a claim that the defendants’ failure to protect him from the imminent peril posed by Valentin abridged his right to substantive due process. The touchstone of the law in this area is the Supreme Court’s opinion in DeShaney. There, a child sued for damages under 42 U.S.C. § 1983, claiming that employees of a state-run social service agency, on notice of a parent’s abusive behavior, nonetheless failed to protect the child from the readily foreseeable danger. See DeShaney, 489 U.S. at 193, 109 S.Ct. at 1001-02. The Court affirmed the entry of summary judgment in defendants’ favor. Chief Justice Rehnquist, writing for the majority, explained that the Due Process Clause ordinarily does not require the state to protect an individual’s life, limb, or property against the marauding of third parties not acting to the state’s behoof. See id. at 196, 109 S.Ct. at 1003. Consequently, “a State’s failure to protect an individual against private violence simply does not constitute a violation of the Due Process Clause.” Id. at 197, 109 S.Ct. at 1004.
Although the DeShaney Court left open the possibility of certain circumscribed exceptions to the general rule of nonliability, Martinez makes no effort to slide within them. He does not argue that he was in the custody of the state, see id. at 198-200, 109 S.Ct. at 1004-06 (discussing right to protection arising in favor of incarcerated prisoners and involuntarily committed mental patients), or that he was in its “functional custody,” see id. at 201 n. 9, 109 S.Ct. at 1006 n. 9 (discussing possible existence of situations analogous to incarceration or institutionalization), or that the state made him more vulnerable to [985]*985Valentin’s actions, see id. at 201, 109 S.Ct. at 1006. Rather, Martinez contends that De-Shaney is altogether inapposite.
To the extent that this contention is based simply and solely on the fact that, unlike in DeShaney, the defendants here are police officers, not social workers, we reject it. Of course, police officers sometimes have an affirmative duty to intervene that is enforceable under the Due Process Clause. For example, “[a]n officer who is present at the scene [of an arrest] and who fails to take reasonable steps to protect the victim of another officer’s use of excessive force can be held liable under section 1983 for his nonfea-sance,” provided that he had a “realistic opportunity” to prevent the other officer’s actions. Gaudreault v. Municipality of Salem, 923 F.2d 203, 207 n. 3 (1st Cir.1990), cert. denied, 500 U.S. 956, 111 S.Ct. 2266, 114 L.Ed.2d 718 (1991); accord O’Neill v. Krzeminski, 839 F.2d 9, 11-12 (2d Cir.1988). But this line of eases does not, as plaintiff importunes, carve out an exception to the DeSha-ney rule. Instead, such cases escape the rule because the aggressor is acting under color of his public office.
Gaudreault illustrates the point. The quoted statement specifically contemplates that the underlying tortious conduct take place within the context of an arrest, interrogation, or similar maneuver, see Gaudreault, 923 F.2d at 206-07 & n. 3, in which a differential exists between the victim and the officer precisely because of the latter’s status as one empowered to enforce the law, coercively if necessary, against the former. Similarly, O’Neill involved the beating of a handcuffed man by law enforcement officers during an interrogation in the detention area of a police station. See O’Neill, 839 F.2d at 10. We cannot imagine a more paradigmatic exercise of state authority than the processes of handcuffing, detaining, and interrogating a citizen. Gaudreault and O’Neill, then, are cases in which the aggressor is acting under color of state law. The DeShaney rule — which addresses the “State’s failure to protect an individual against private violence,” DeShaney, 489 U.S. at 197, 109 S.Ct. at 1004 (emphasis supplied) — is not implicated in such cases because the violence in question is not private but “public,” i.e., attributable to state action.4
Private violence — even private violence engaged in by one who happens to work for the state — has different legal ramifications than violence attributable to state action. See, e.g., Hughes v. Halifax County Sch. Bd., 855 F.2d 183, 186-87 (4th Cir.1988) (distinguishing private actions of county maintenance workers from cases in which “the actions complained of were committed while the defendants were purporting to act under the authority vested in them by the state, or were otherwise made possible because of the privileges of their employment”), cert. denied, 488 U.S. 1042, 109 S.Ct. 867, 102 L.Ed.2d 991 (1989).
Thus we recently held, in light of DeShaney, that a district attorney’s office had no constitutional obligation to protect a citizen against self-inflicted private violence (there, noncustodial suicide) alleged to have been caused by the state’s implication of him in a multiple murder case. See Souza v. Pina, 53 F.3d 423, 426-27 (1st Cir.1995). Interpreting DeShaney to say that the state has no generalized duty to protect its citizens from violence except when it sets the stage by acting affirmatively (as in a custodial setting), see id. at 426, we concluded that, although the state’s acts may have “rendered [the decedent] more vulnerable to danger in the sense that those acts may have exacerbated — or even brought about — [the decedent’s] suicidal tendencies ... these are not the kind of [986]*986‘affirmative acts’by the state that would give rise to a constitutional duty to protect.” Id. at 426 (citing Monahan v. Dorchester Counseling Ctr., Inc., 961 F.2d 987, 992-93 (1st Cir.1992)).
Translated to the police milieu, these cases mean that when an on-duty police officer witnesses violence, the existence vel non of a constitutional duty to intervene will most often hinge on whether he is witnessing private violence or violence attributable to state action. It remains to be seen how and where the line that separates one from the other should be drawn.
B. Private Action.
In attempting to distinguish private violence from violence attributable to state action for purposes of applying the DeShaney rule, courts must beware simplistic solutions. To be sure, violence is attributable to state action if the perpetrator is acting under color of state law, see, e.g., Earnest v. Lowentritt, 690 F.2d 1198, 1200 (5th Cir.1982) (“Section 1983 does not reach all constitutional injuries, but only those caused by persons acting ‘under color of state law.’ ”), but that is a virtual tautology. Furthermore, the construct — “acting under color of state law”— rarely depends on any single, easily determinable fact, such as a policeman’s garb, see, e.g., Stengel v. Belcher, 522 F.2d 438, 441 (6th Cir.1975) (explaining that whether a police officer is “in or out of uniform is not controlling”), cert. dismissed, 429 U.S. 118, 97 S.Ct. 514, 50 L.Ed.2d 269 (1976), duty status, see, e.g., Pitchell v. Callan, 13 F.3d 545, 548 (2d Cir.1994) (explaining that “whether an officer was on or off duty when the challenged incident occurred” is not dispositive); Stengel, 522 F.2d at 441 (same), or whereabouts, see, e.g., Delcambre v. Delcambre, 635 F.2d 407, 408 (5th Cir.1981) (per curiam) (holding that a police chiefs assault on a private citizen was not conduct under color of law even though it occurred at police headquarters). Nor does “acting under color of state law” depend on whether an officer stays strictly within the line of duty, or oversteps it. See Monroe v. Pape, 365 U.S. 167, 172, 81 S.Ct. 473, 476, 5 L.Ed.2d 492 (1961); Screws v. United States, 325 U.S. 91, 111, 65 S.Ct. 1031, 1040, 89 L.Ed. 1495 (1945). For instance, a police officer who exercises, but misuses or exceeds, his lawfully possessed authority is generally thought to be acting under color of law. See, e.g., Gibson v. City of Chicago, 910 F.2d 1510, 1518 (7th Cir.1990).
The point is that segregating private action from state action calls for a more sophisticated analysis. In general, section 1983 is not implicated unless a state actor’s conduct occurs in the course of performing an actual or apparent duty of his office, or unless the conduct is such that the actor could not have behaved in that way but for the authority of his office. Thus, whether a police officer is acting under color of state law turns on the nature and circumstances of the officer’s conduct and the relationship of that conduct to the performance of his official duties. See Pickrel v. City of Springfield, 45 F.3d 1115, 1118 (7th Cir.1995); Anthony v. County of Sacramento, 845 F.Supp. 1396, 1400 (E.D.Cal.1994).
We think this focus follows inexorably from West, where the Court wrote that “[t]he traditional definition of acting under color of state law requires that the defendant ... have exercised power ‘possessed by virtue of state law and made possible only because the wrongdoer is clothed with the authority of state law.’ ” West, 487 U.S. at 49, 108 S.Ct. at 2255 (quoting United States v. Classic, 313 U.S. 299, 326, 61 S.Ct. 1031, 1043, 85 L.Ed. 1368 (1941)). Hence, a person acts under color of state law “when he abuses the position given to him by the State.” Id. at 50, 108 S.Ct. at 2255. The key determinant is whether the actor, at the time in question, purposes to act in an official capacity or to exercise official responsibilities pursuant to state law. See id.
Logically, then, not every action undertaken by a person who happens to be a police officer is attributable to the state. Though “under ‘color’ of law means under ‘pretense’ of law,” even so, the acts of state officials “in the ambit of their personal pursuits” are not state action. Screws, 325 U.S. at 111, 65 S.Ct. at 1040; see also Gibson, 910 F.2d at 1518. Accordingly, a policeman’s private conduct, outside the line of duty and [987]*987unaided by any indicia of actual or ostensible state authority, is not conduct occurring under color of state law. See Barna v. City of Perth Amboy, 42 F.3d 809, 816 (3d Cir.1994); United States v. Tarpley, 945 F.2d 806, 809 (5th Cir.1991), cert. denied, 504 U.S. 917, 112 S.Ct. 1960, 118 L.Ed.2d 562 (1992); Dang Vang v. Vang Xiong X. Toyed, 944 F.2d 476, 479 (9th Cir.1991); Murphy v. Chicago Transit Auth., 638 F.Supp. 464, 467 (N.D.Ill.1986); Johnson v. Hackett, 284 F.Supp. 933, 937 (E.D.Pa.1968). Even though “acting under color of law” includes “acting under pretense of law” for purposes of a state action analysis, there can be no pretense if the challenged conduct is not related in some meaningful way either to the officer’s governmental status or to the performance of his duties.
C. Separating Wheat from Chaff.
Explicating the standard for segregating private action from action attributable to the state does not complete our task. Since the private conduct of police officers does not constitute action attributable to the state and, therefore, does not give rise to section 1983 liability under DeShaney or otherwise, we must determine whether Valentin, at the time and place in question, was engaged in purely personal pursuits or, conversely, whether he was acting under color of state law. To do so, we must assess the nature of his conduct in light of the totality of surrounding circumstances. See Pitchell, 13 F.3d at 548; Revene v. Charles County Comm’rs, 882 F.2d 870, 872-73 (4th Cir.1989); Traver v. Meshriy, 627 F.2d 934, 938 (9th Cir.1980).
Here, the record is transpicuously clear that throughout the course of Martinez’ ordeal Valentin did not exercise, or purport to exercise, any power (real or pretended) possessed by virtue of state law. To the contrary, Valentin was bent on a singularly personal frolic: tormenting an acquaintance.5 Though on duty and in uniform, Valentin’s status as a police officer simply did not enter into his benighted harassment of his fellow officer. Hazing of this sort, though reprehensible, is not action under color or pretense of law.
Nor can it be said that Valentin’s actions were in any meaningful way related either to his official status or to the performance of his police duties. In this regard, the case bears a resemblance to Delcambre. There, the Fifth Circuit ruled that the plaintiff, who had been assaulted on the premises of the municipal police station by her brother-in-law, the police chief, had no cognizable claim under 42 U.S.C. § 1983. See Delcambre, 635 F.2d at 408. The assault arose out of a family squabble, and the court found that the police chief, though on duty, “was not acting under color of law as required for liability under [section 1983].” Id.
To be sure, Valentin shot Martinez with his service revolver, and in that sense it might be argued that the shooting was made possible by Valentin’s status as a police officer. See Cassady v. Tackett, 938 F.2d 693, 695 (6th Cir.1991) (concluding that, in “allegedly flourishing and threatening to use his gun” against a eoworker, the defendant acted under color of state law because he “had authority or power to carry the gun in the jail only because he was [the county’s] elected jailer”). This argument succumbs for a very basic reason: plaintiff did not proffer it either in the district court or in his appellate brief. The argument is, therefore, not properly before us. See United States v. Slade, 980 F.2d 27, 30 n. 3 (1st Cir.1992) (stating that theories not briefed on appeal are waived); Teamsters, Chauffeurs, Warehousemen & Helpers Union v. Superline Transp. Co., 953 F.2d 17, 21 (1st Cir.1992) (“If any principle is settled in this circuit, it is that, absent the most extraordinary circumstances, legal theories not raised squarely in the lower court cannot be broached for the first time on appeal.”).
Even if the argument were properly before us, we would not embrace it. We do not think it is reasonable to hold that every use of a policeman’s gun, even in the course of purely personal pursuits, creates a cause of action under section 1983. Instead, we are of the view that the context in which a service [988]*988revolver is used, not just the mere fact of its use, must be consulted to determine the constitutional relevance of the officer’s conduct. See Payne v. Government of D.C., 559 F.2d 809, 825 n. 9 (D.C.Cir.1977). Consequently, “[w]hile a police officer’s use of a state-issue weapon in the pursuit of private activities will have ‘furthered’ the § 1983 violation in a literal sense,” a court needs “additional indi-cia of state authority to conclude that the officer acted under color of state law.” Barna, 42 F.3d at 817-18 (holding that “unauthorized use of a police-issue nightstick is simply not enough to color [a] clearly personal family dispute with the imprimatur of state authority”).
Here, plaintiff has not produced any evidence tending to show that his tormentor, when brandishing the firearm, was exercising or purporting to exercise police power.6 In the absence of any additional indicia of state action, we believe that the unauthorized use of a government-issue weapon is too attenuated a link to hold together a section 1983 claim. See Barna, 42 F.3d at 818-19; Payne, 559 F.2d at 825 n. 9; see also Bonsignore v. City of N.Y., 683 F.2d 635, 638-39 (2d Cir.1982) (holding that a police officer who wounded his wife and killed himself using a gun which he was authorized to carry because of his status as an officer “was not acting under color of state law since his actions were not ‘committed in the performance of any actual or pretended duty,’ but were performed ‘in the ambit of [his] personal pursuits’”) (quoting Screws, 325 U.S. at 111, 65 S.Ct. at 1040; Johnson, 284 F.Supp. at 937).
We add an esehatocol of sorts. Even if a constitutional duty to intervene conceivably could be dragooned from these facts, then in that event the location of this case in the penumbra of DeShaney dictates that the defendants nonetheless would enjoy qualified immunity and, since appellant’s suit only seeks money damages, the defendants would be entitled to an affirmance on this alternative ground. See, e.g., Garside, 895 F.2d at 48-49 (explaining that a grant of summary judgment can be affirmed on any independently sufficient ground made manifest in the record). We elaborate below.
“In analyzing a claim of qualified immunity, ... we are concerned with clearly established constitutional or statutory rights of which a reasonable officer would have known at the time he took action.” Crooker v. Metallo, 5 F.3d 583, 584 (1st Cir.1993) (emphasis supplied). When used in this context, the phrase “clearly established” has a well-defined meaning. It denotes that at the time the challenged conduct occurred the contours of the right were sufficiently plain that a reasonably prudent state actor would have realized not merely that his conduct might be wrong, but that it violated a particular constitutional right. See Anderson v. Creighton, 483 U.S. 635, 640, 107 S.Ct. 3034, 3039, 97 L.Ed.2d 523 (1987); Buenrostro v. Collazo, 973 F.2d 39, 42 (1st Cir.1992). The inquiry into the nature of a constitutional right for the purpose of ascertaining clear establishment seeks to discover whether the right was reasonably well settled at the time of the challenged conduct and whether the manner in which the right related to the conduct was apparent. See Wiley v. Doory, 14 F.3d 993, 995 (4th Cir.1994) (Powell, J., sitting by designation). In mounting this inquiry, courts may neither require that state actors faultlessly anticipate the future trajec[989]*989tory of the law, see Crooker, 5 F.3d at 585 (noting that a state actor is not. “expected to carry a crystal ball”), nor permit claims of qualified immunity to turn on the eventual outcome of a hitherto problematic constitutional analysis, see, e.g., Collins v. Marina-Martinez, 894 F.2d 474, 478 (1st Cir.1990) (recognizing that “a plaintiff who is entitled to prevail on the merits is not necessarily entitled to prevail on the issue of qualified immunity”); accord Amsden v. Moran, 904 F.2d 748, 751-52 (1st Cir.1990) (citing other cases), cert. denied, 498 U.S. 1041, 111 S.Ct. 713, 112 L.Ed.2d 702 (1991).
Here, there can be no doubt that, at the moment the maiming of Martinez materialized, legitimate questions abounded as to whether the conduct at issue violated Martinez’ constitutional rights. After all, DeShaney had not yet been decided; thus, the whole question of a constitutional duty to intervene was cloaked in uncertainty. Even now, with the guidance furnished by the De-Shaney Court, the precise contours of the rule as it applies to onlooker officers are murky. Consequently, even if 'Martinez had some basis for a claim that the defendants owed him a duty grounded in the Constitution, the dimensions of the right were dimly perceived (if perceived at all). It follows inexorably that the defendants would be entitled to qualified immunity and, hence, entitled to brevis disposition.
D. Other Theories.
In addition to his principal due process claim, Martinez advances several other theories. All are unavailing. We mention three of them (rejecting the remainder without further elaboration).
1. Violation of Local Law. Martinez urges that the defendants’ breach of a provision of Puerto Rico’s Civil Code, P.R.Laws Ann. tit. 25, § 1003 (1980),7 furnishes a basis for liability under 42 U.S.C. § 1983. He is wrong.
It is established beyond peradventure that a state actor’s failure to observe a duty imposed by state law, standing alone, is not a sufficient foundation on which to erect a section 1983 claim. See, e.g., Amsden, 904 F.2d at 757; Chongris, 811 F.2d at 42-43. Although it is true that constitutional significance may attach to certain interests created by state law, see, e.g., Chongris, 811 F.2d at 43 (recognizing that “property rights, while protected by the federal Constitution, are creatures of state law”), not every transgression of state law does double duty as a constitutional violation. The Constitution is a charter of carefully enumerated rights and responsibilities, defining the relationship between the people and a government of limited powers. Its scope and application are necessarily determined by its own terms. Though grand in its design and eloquent in its phrasing, the Constitution is not an empty ledger awaiting the entry of an aggrieved litigant’s recitation of alleged state law violations — no matter how egregious those violations may appear within the local legal framework.8
Moreover, while the plaintiff states that section 1003 creates a constitutionally protected “entitlement” under Board of Regents v. Roth, 408 U.S. 564, 576-77, 92 S.Ct. 2701, 2708-09, 33 L.Ed.2d 548 (1972), he does not develop the thesis — and we do not see how Roth applies. Neither Roth’s focus nor its procedural design bears any similarity to the case at hand. For one thing, the Roth Court’s conception of a cognizable constitutional entitlement was limited to property interests. See id. (citing Goldberg v. Kelly, 397 U.S. 254, 90 S.Ct. 1011, 25 L.Ed.2d 287 (1970)). We fail to intuit how Roth supports the plaintiffs claim that he had an entitlement, pursuant to section 1003, to be protected in his physical person. For another thing, [990]*990the remedial framework contemplated by Roth — procedural due process, principally in the form of notice and a hearing, see id. at 577, 92 S.Ct. at 2709 — has no applicability at all to Martinez’ remonstrance. Whatever other uncertainties may plague this case, it is clear that Martinez is claiming a substantive due process violation, not a procedural due process violation. See, e.g., Amsden, 904 F.2d at 753-54 (delineating differences).
In sum, Roth is a round hole, and Martinez’ square peg of a case does not fit within it.
2. Equal Protection. The plaintiff makes the bold assertion that he was denied lights secured to him under the Equal Protection Clause because, were he a private citizen, the defendants would almost certainly have come to his rescue. He does not embellish this ipse dixit in any way.9 Consequently, it does not assist his cause. “It is settled in this circuit that issues adverted to on appeal in a perfunctory manner, unaccompanied by some developed argumentation, are deemed to have been abandoned.” Ryan v. Royal Ins. Co. of Am., 916 F.2d 731, 734 (1st Cir.1990); accord United States v. Zannino, 895 F.2d 1, 17 (1st Cir.), cert. denied, 494 U.S. 1082, 110 S.Ct. 1814, 108 L.Ed.2d 944 (1990); Collins v. Marina-Martinez, 894 F.2d 474, 481 n. 9 (1st Cir.1990). So it is here: the plaintiffs fleeting reference to equal protection does not succeed in preserving the issue for review.10
3. Supervisory Liability. Finally, the plaintiff maintains that Trinidad, if not hable under section 1983 as an onlooker officer, may be held liable qua shift supervisor for Valentin’s acts. “Supervisory liability attaches only if a plaintiff can demonstrate by material of evidentiary quality an affirmative link between the supervisor’s conduct and the underlying section 1983 violation.” Maldonado-Denis v. Castillo-Rodriguez, 23 F.3d 576, 583 (1st Cir.1994); see also Febus-Rodriguez v. Betancourt-Lebron, 14 F.3d 87, 92 (1st Cir.1994); Gutierrez-Rodriguez v. Cartagena, 882 F.2d 553, 562 (1st Cir.1989). Because no underlying constitutional violation in fact occurred, see supra Part III(C), no supervisory liability can be attributed to Trinidad under section 1983.11
IV. CONCLUSION
We need go no further. Because the defendants’ failure to intervene and protect the plaintiff against Valentin’s private actions, though regrettable, cannot be said to have violated rights secured to the plaintiff by the United States Constitution, see DeShaney, 489 U.S. at 196-97, 109 S.Ct. at 1003-04, the district court did not err in summarily disposing of the federal claims. And, once the court determined so far in advance of trial that no legitimate federal question existed, the jurisdictional basis for plaintiffs pendent claims under Puerto Rico law evaporated. See Brennan, 888 F.2d at 196. Thus, the [991]*991court properly dismissed the balance of the complaint.12
AFFIRMED.