dissenting:
The structure we are talking about in this case is described in defense Exhibit 1 admitted into evidence at the suppression hearing. Tr. at 38. Defense counsel acknowledged that the drawing is not to scale, and he inserted eonclusory word descriptions which we disregard as unsupported by the testimony, and contrary to factual findings by the magistrate judge, R & R at 10, which are not clearly erroneous. Tr. at 35, 37. Additionally, in his testimony, Officer McConkey corrected the failure of the drawing to show a door from the small furnace room into the adjacent area. Id. at 35-36. The drawing, however, reveals some important facts bearing on the reasonableness of the officers’ entry; so I am attaching a copy.
According to Exhibit 1 and testimony at the hearing, the building is a very small single-story detached cinder block structure with a flat corrugated iron roof. There is a single, barred window, in front, a door and a garage door about seven feet high and fourteen feet wide. Id. at 11. The drawing shows that the “garage” is actually a work area occupying the entire north side, and probably more than one-half of this small building. There are three small rooms on the south side of the structure. The rooms have no interconnecting doors or hallway. Rather, they open directly into the work area, so the only way to go from one room to the other is to go into the work area. The rooms are, therefore, auxiliary to the work area, not to each other. There is no lavatory, bath or shower, and no kitchen. Clearly, as the magistrate judge found, this is no residence, R & R at 10, and there is no evidence that anyone lived on the premises. Id. at 14. It is a small, light industrial structure — a commercial building, as the lower court found, as shown by its analysis, id. at 15-30, and direct statement. Id. at 25. Furthermore, when Officers McConkey and Cannon drove past the building, Officer Cannon identified it as “the old honey manufacture.” Tr. at 10-11. The dominant feature of this small commercial building, both by the space it occupies, and the configuration of the rooms which open off the space instead of into each other, is the “garage” or work area.
When officers McConkey and Cannon, on a routine patrol schedule, drove past this unlighted commercial building at approximately 11:15 p.m., they saw that the “garage” door was open, noting that that was an abnormal circumstance, especially at night. Officer McConkey knew from ten years’ personal experience in the area that the open door was unusual. He had never seen it open before, and had never seen “anybody around what was a business.” Id. at 9, 11.
*541Accordingly, after 'officer McConkey dropped off officer Cannon at his house, he returned to the building and positioned his police car so that the headlights and spotlight illuminated the entire work area, fully visible because of the open door. Officer McConkey then got out of his squad car, walked into the open area, looked around, and saw nothing unusual. He then walked over to the three doors opening off the work area. One of those doors was partly open. Id. at 16. The officer then briefly opened the doors, shined his flashlight around the interior of each small room and, in the process, yelled “anybody in there?” Id. In the last room he saw lab equipment from the doorway and a TV monitor with a cable running to an observation camera in the window by the door in front. He also smelled a pungent odor which caused his tongue to tingle. Id. at 15.
With the “garage” door up, this structure and its contents were almost entirely exposed and accessible to anyone. One of the interior doors was partly open. It was the middle of the night. The commercial nature of the building and the fact that it was dark and appeared deserted caused the officer on patrol to investigate. That investigation was limited to shining a flashlight, looking, and assessing if anyone was there. Nothing was touched; the officer did not rummage through any of the building’s contents. He only looked.
The officer conducted this check of the premises to protect the owner’s property and safeguard the community, not to search for evidence against the owner or tenant. The average citizen will be dumbfounded at the notion that this officer was prohibited by the Federal Constitution from checking on the safe condition of these premises, under these circumstances, in the manner described. Subsequent thirty-second entries by Officer McConkey’s supervisor, and a single narcotics officer, and a brief entry by the hazardous materials team did nothing to enlarge the scope of the original entry by Officer MeCon-key. There was no rummaging. Then a warrant was promptly sought, as early as 3:00 a.m.
Society would not only tolerate this level of intrusion into a mostly open commercial building at night, it would demand it.
A.
It is questionable whether the Fourth Amendment is implicated at all when an officer on patrol enters a commercial structure standing wide open to “check out” what can already be seen from outside.
Although at one time the concept of “search” hinged on principles of physical intrusion or trespass, see, e.g., Boyd v. United States, 116 U.S. 616, 6 S.Ct. 524, 29 L.Ed. 746 (1886), over the last several decades, the presence or absence of a physical intrusion has ceased to be the focal point of Fourth Amendment analysis. Instead, the Supreme Court has made it clear that a search occurs only when a reasonable expectation of privacy is impinged. Katz v. United States, 389 U.S. at 353, 88 S.Ct. at 512 (“[T]he reach of [the Fourth Amendment] cannot turn upon the presence or absence of a physical intrusion.”). In Katz, the Supreme Court, “for the first time explicitly overruled the ‘physical penetration’ and ‘trespass’ tests enunciated in earlier decisions.” Desist v. United States, 394 U.S. 244, 250, 89 S.Ct. 1030, 1034, 22 L.Ed.2d 248 (1969). This Circuit has specifically held that mere entry into private premises does not automatically implicate the Fourth Amendment. Artes-Roy v. Aspen, 31 F.3d 958, 962 (10th Cir.1994) (concluding inspector’s opening door to plaintiffs residence and stepping into entryway without warrant or proper consent did not implicate the Fourth Amendment).
But assuming arguendo that the Fourth Amendment was implicated at some point here because Officer McConkey opened two doors (the third was already ajar) and shined his light inside, the officer’s conduct was not constitutionally unreasonable. From earliest times in England and in this country emphasis has been placed on the role played by the police in preventing crime, preserving order, and protecting persons and property. I ABA Standards of Criminal Justice §§ l-2.1(a), 1-2.2(b) (2d ed. 1980).
[M]ost police efforts have been directed at making their presence felt to the maximum *542degree through random and conspicuous patrol — seeking thereby to create an impression of police omnipresence. In the course of their patrol activities, police identify and correct conditions, such as open premises, that increase the opportunity for criminal, activity and also check out suspicious circumstances and persons.
Id. § l-2.2(b).
It is also a recognized fact that the police perform this patrol and check function as a result not just of community expectation but community pressure. Thus, “commercial interests, for example, typically want more time devoted to checking the security of their establishments.... ” Id. § 1-2.1. In short, cheeking out commercial premises inexplicably left not just unlocked but wide open in the middle of the night is not an activity society tolerates; it is one society demands. See Wayne R. LaFave, Search and Seizure: A Treatise on the Fourth Amendment § 6.6(b) (2d ed. 1987) (“Indeed, entry would be permissible when commercial premises are found to be unlocked and unattended in the evening hours.”).
State courts have long recognized that security checks by patrolling officers in no way offend the reasonableness requirement of the Fourth Amendment. See, e.g., Alaska v. Meyers, 601 P.2d 239 (Alaska 1979); California v. Parra, 30 Cal.App.3d 729, 106 Cal.Rptr. 531, cert. denied, 414 U.S. 1116, 94 S.Ct. 849, 38 L.Ed.2d 743 (1973); Illinois v. Gardner, 121 Ill.App.3d 464, 76 Ill.Dec. 761, 459 N.E.2d 676 (1984). While the majority opinion downplays the significance of these cases by pointing out that the exact same reasoning has not appeared in cases from federal courts, I see it differently. State courts are the natural source for cases on this subject. Security patrols of business and private premises are a function and concern of local law enforcement and communities, and typically involve state law. Thus, the issues will naturally be played out more in state than federal courts.
Regardless, it is beyond dispute that the Supreme Court has recognized that police officers perform a community caretaking function wholly separate from the detection and arrest of criminals. Cady v. Dombrow-ski, 413 U.S. 433, 439, 93 S.Ct. 2523, 2527, 37 L.Ed.2d 706 (1973); see also United States v. King, 990 F.2d 1552, 1560 (10th Cir.1993). While the Court has not explicitly extended this self-evident concept to security cheeks of commercial premises, it has not ruled that such a function would violate the Fourth Amendment. To the contrary, there are significant indications it would not do so. In New York v. Burger, 482 U.S. 691, 700, 107 S.Ct. 2636, 2642, 96 L.Ed.2d 601 (1987), the Court recognized that “[a]n expectation of privacy in commercial premises ... is different from, and indeed less than, a similar expectation in an individual’s home.” And where, as in this case, the security check is to protect the owner’s property, not to incriminate the owner, the Court’s observation in Camara v. Municipal Court, 387 U.S. 523, 537, 87 S.Ct. 1727, 1735, 18 L.Ed.2d 930 (1967) is apt: Where searches are “neither personal in nature nor aimed at the discovery of evidence of a crime, they involve a relatively limited invasion of ... privacy.” Furthermore, the purpose of the security check serves to limit the degree of intrusiveness of the “search” because “the scope of [the] search must be strictly limited to the circumstances which rendered its initiation permissible.” Terry v. Ohio, 392 U.S. 1, 19, 88 S.Ct. 1868, 1878, 20 L.Ed.2d 889 (1968).
This latter restriction in the scope of the entry is one of the reasons why I do not accept the premise of the majority that, for instance, the confidentiality of law firm files might be compromised by the entry through an open door of a patrolling officer anxious to check on the safety of the property. Rummaging is not part of a security check, and it is absent in this case.
In any event, I see no reason why this case requires us to adopt or reject a broad “security check” exception to the warrant requirement covering every imaginable situation. I summarize where I began: Fourth Amendment issues are highly fact specific, resolved on a case-by-case basis, with reasonableness as the touchstone. See Cooper v. California, 386 U.S. 58, 59, 87 S.Ct. 788, 789, 17 L.Ed.2d 730 (1967); see also, e.g., Florida v. Jimeno, 500 U.S. 248, 250, 111 S.Ct. 1801, 1803, 114 L.Ed.2d 297 (1991); Illinois v. Rodriguez, *543497 U.S. 177, 185, 110 S.Ct. 2793, 2799, 111 L.Ed.2d 148 (1990); NTEU v. Von Raab, 489 U.S. 656, 665, 109 S.Ct. 1384, 1390, 103 L.Ed.2d 685 (1989); United States v. Montoya de Hernandez, 473 U.S. 531, 537, 105 S.Ct. 3304, 3308, 87 L.Ed.2d 381 (1985); United States v. Sharpe, 470 U.S. 675, 682, 105 S.Ct. 1568, 1573, 84 L.Ed.2d 605 (1985); Pennsylvania v. Mimms, 434 U.S. 106, 108-09, 98 S.Ct. 330, 332, 54 L.Ed.2d 331 (1977); United States v. Chadwick, 433 U.S. 1, 7, 97 S.Ct. 2476, 2481, 53 L.Ed.2d 538 (1977); Cady v. Dombrowski, 413 U.S. 433, 439, 93 S.Ct. 2523, 2527, 37 L.Ed.2d 706 (1973); Cooper v. California, 386 U.S. at 62, 87 S.Ct. at 791 (1967); United States v. Carr, 939 F.2d 1442, 1448 (10th Cir.1991) (providing reasonableness is the overriding test of compliance with the Fourth Amendment).
We are not dealing with any of the hypo-theticals postulated by the majority — only with the reasonableness of Officer McCon-key’s entry into a dark, wide-open commercial building, in the middle of the night, to shine his flashlight around for the purpose of protecting the premises. He did no rummaging, conducted no search for evidence. If the Fourth Amendment was involved at all, or at some point in this initial check of rooms, then, in respectful disagreement with the majority, I think the activity was reasonable.
B.
The appellants have waived any separate argument on appeal that the subsequent entries by McConkey’s supervisor, Sergeant Wood, Officer Lyman of the narcotics squad and technician Kevin Greer of the Salt Lake County Fire Department’s Hazardous Materials Unit, violated the Fourth Amendment. Their brief on appeal focuses exclusively on the lawfulness of officer McConkey’s initial entry, as did their objections to the magistrate judge’s report and recommendation, and their argument to the district court. Significantly, the magistrate judge identified MeConkey’s entry as the only issue. R & R at 13. At the suppression hearing the appellants put on no evidence to show that the subsequent entries exceeded the scope of officer McConkey’s entry or were extended in time — either response time or time in the building and, those points are not pursued at any juncture by the appellants, either below or in their arguments on appeal. Consistent with the appellants’ approach, the majority opinion focuses exclusively on the initial entry by McConkey.
However, assuming for purposes of argument that we have a real issue before us separately challenging the reasonableness of the subsequent entries, that issue must also be resolved in favor of the district court’s denial of the motion to suppress.
As explained above, the recognizable privacy expectations of these lessees were reduced to begin with because of the commercial nature of the premises. These expectations were further diminished by the fact that they (apparently) left the building literally wide open.
Officer McConkey lawfully, as I contend, checking the well-being of the owner’s property, saw the room full of laboratory equipment, and could smell and taste from the air its chemical product. At that point what little expectation of privacy the lessee’s had in the lab room was already lost. It is hard to explain on any practical basis how subsequent officers’ confirming observations of the same thing McConkey saw, smelled, and tasted constituted any more than a de mini-mus intrusion on what was no longer private. This is so regardless of the difference in their reasons for looking at what McConkey had already looked at.
The Fifth Circuit, for example, has previously noted that
the fourth amendment protects the citizen against invasion of privacy. Once that interest is invaded legally by a [government agent], the citizen has lost his reasonable expectation of privacy to the extent of the invasion. As this court has held repeatedly, additional investigators or officials may therefore enter a citizen’s property after one official has already intruded legally.
Vance v. United States, 676 F.2d 183, 188 n. 8 (5th Cir.1982); see, e.g., United States v. Brand, 556 F.2d 1312, 1317 (5th Cir.1977) (concluding that when one law enforcement official justifiably enters dwelling without a *544warrant, later arrivals “may join their colleagues even though the exigent circumstances justifying the initial entry no longer exist”), cert. denied, 434 U.S. 1063, 98 S.Ct. 1237, 55 L.Ed.2d 763 (1978); United States v. Green, 474 F.2d 1385, 1390 (5th Cir.) (“Where a lawful intrusion has already occurred ... invasion of privacy is not increased by an additional officer ... who is an expert in identifying the type of contraband discovered, entering the premises to confirm the belief of the officer and to take custody of the evidence.”), cert. denied, 414 U.S. 829, 94 S.Ct. 55, 38 L.Ed.2d 63 (1973).
Two further facts in this case-by-case, fact-intensive inquiry, support the de minimus additional intrusion argument. First, there was no rummaging. The individuals who subsequently entered the building did not appreciably expand the scope of what Officer MeConkey did at the outset. No drawers were opened; there was no search of papers or other effects or paraphernalia.1 The other officers only observed what MeConkey observed, in plain view. There is no evidence to the contrary proffered by the defense. MeConkey looked; the others looked — all at the same thing.
The intrusion was further minimized by the limited number of people who entered the structure. Although several different groups responded to the hazardous situation, only a few individuals actually entered the building. Sergeant Wood walked into the open area for about thirty seconds. Narcotics Officer Lyman was the only agent from metro narcotics to enter the structure, also for about thirty seconds. Tr. at 20-21. Hazardous materials team members were at the scene, but no testimony was elicited about the details of their entry. The affidavit mentions only Greer. The remaining officers, including officers from the Utah Division of Investigations who subsequently arrived, apparently never entered the premises and secured the building from the outside. Def.’s Ex. 2, Attach. C ¶ 12.
Second, the events were reasonably related in time, considering that it was the middle of the night, and brief. Officer MeConkey was in the braiding for three to four minutes. R & R at 10. Sergeant Wood arrived about ten to fifteen minutes later, Tr. at 40, and, as indicated above, was in the building only thirty to forty-five seconds. R & R at 10. Officer Lyman of narcotics was in the braiding only thirty to forty-five seconds. Apparently, technician Greer was in the building only enough longer to look at labels on some containers, draw a building diagram, and take a sample of the air. There is no evidence showing when officer Lyman and technician Greer arrived on the scene, but it would not have been more than an hour or two at the outside because a search warrant was applied for as early as 3:00 a.m. Id. at 11. It is noteworthy that the defense made no issue of the time interval as regards the arrival of Lyman and Greer, and introduced no evidence on the subject. Thus, as indicated above, I regard any argument on elapsed time as waived.2
*545Katz did not purport to freeze Fourth Amendment analysis into warrants and pigeon holes. The warrant exceptions then and thereafter recognized are simply ways of expressing reasonableness for Fourth Amendment purposes. As indicated above, the Fourth Amendment text and, therefore its test, is reasonableness. See Jimeno, 500 U.S. at 250, 111 S.Ct. at 1803; Montoya de Hernandez, 473 U.S. at 537, 105 S.Ct. at 3308; Sharpe, 470 U.S. at 682, 105 S.Ct. at 1573; Mimms, 434 U.S. at 108-09, 98.S.Ct. at 332; Chadwick, 433 U.S. at 7, 97 S.Ct. at 2481. Any other view would have made our decision in Artes-Roy v. Aspen, 31 F.3d 958 (10th Cir.1994), impossible.
These entries, in my opinion, were not unreasonable under the Fourth Amendment. Accordingly, I respectfully dissent.
. Apparently, according to the affidavit for the warrant, introduced by the defense, technician Greer looked at labels on the chemical containers in full view, and sampled the air for dangerous substances, and found the air was in fact dangerous.
. The hazard posed by the chemicals present in this case created a public safety issue from the outset, and was at all times inextricably intertwined with the perceived criminal conduct — -a methamphetamine laboratory. Although officer MeConkey could not identify the kind of lab he saw, or the chemical smell, the chemical presence in the air was so strong it made his tongue tingle, and he would not enter the lab room out of fear of contamination. Tr. at 46. After Sergeant Wood confirmed what MeConkey saw, both narcotics and HAZMAT were called. According to the affidavit, Greer of HAZMAT could smell and identify the chemical from outside the building. He went into the area and sampled the air, finding it so dangerous that he ordered the building evacuated. Def's Ex. 2, Aff. ¶ 11. All of this would justify a warrantless entry by itself. See, e.g., United States v. Erb, 596 F.2d 412 (10th Cir.1979) (hazards posed by methamphetamine lab on premises contributed to justifiable war-rantless entry based on exigent circumstances); United States v. Whitten, 706 F.2d 1000, 1014 (9th Cir.1983) (risk of explosion of a methamphetamine lab in operation presented an exigent circumstance that would have justified an immediate warrantless search); United States v. Spinelli, 848 F.2d 26 (2d Cir.1988) (officers failure to follow knock and announce statute in exercising warrant was justified by exigent circumstances due in part to the violent and flammable nature of methamphetamine, which defendant *545was believed to have been producing in his home).
However, the government, for some reason not appearing in the record, did not bring in Greer to testify, allowing McConkey's uneducated statement that no hazard existed to stand. Tr. at 21. This led to a similar finding by the magistrate judge. R & R at 6,