Defendant Gomez was charged with possession of marijuana and possession of heroin with intent to deliver. A jury found him guilty as charged. Gomez appeals that conviction, claiming that: (1) certain evidence seized by law enforcement officers in a search of his premises should have been suppressed; (2) the trial court erred in limiting defendant’s right to cross examine a police officer at the suppression hearing; (3) he was denied due process by virtue of the state’s failure to disclose before trial certain photographs material to the search and seizure issue; (4) the trial court erred in permitting a federal narcotics agent to give his opinion regarding defendant’s alleged intent to deliver the narcotics seized; and (5) the evidence was insufficient to support the jury’s finding that the defendant intended to deliver narcotics.
On May 18, 1976, Lt. Galland, director of the city-county narcotics division of Canyon County, submitted an “Affidavit in Support of Search Warrant” to a magistrate. The magistrate then issued a search warrant directing “ANY SHERIFF, CONSTABLE, MARSHAL OR POLICEMAN” in Canyon County to search defendant’s residence described as:
“That certain single-story white frame house located at Route 3, Parma, Idaho, on a road known as Highway 18 or Roswell Boulevard, and particularly located in the middle of a block on the east side of the highway between Wendell Street and Park Street and identified with the number 204 posted on the front of the house under the possession and control of one Carlos Gomez.”
After warrants for the arrest of Gomez and a search of his home were issued, a number of officers met in the basement of the Canyon County sheriff’s office in order to determine how to proceed to execute the warrants. Agent Johnson, a special agent for the State Bureau of Narcotics, testified that at such time he personally observed what he thought were the original arrest and search warrants. Whether or not he had actually seen them, it is certain that he was aware that the warrant for the arrest of Gomez and the warrant to search the defendant’s premises had been issued.
Thereafter, a number of officers proceeded toward the city of Parma in several cars. Lt. Galland had possession of the arrest and search warrants. Agent Johnson and Officer Galland were in separate vehicles. When the officers arrived in Parma, Lt. Galland proceeded to arrest the defendant *805at a location not far from defendant’s residence. At this time, Agent Johnson was radioed and informed that Gomez was being arrested, and that he should proceed to the Gomez residence in order to “secure the premises.” According to Agent Johnson, the officers desired to make sure that no one entered or left the premises and that no evidence would be destroyed.
Agent Johnson and two other officers proceeded to the defendant’s house without the warrant, knocked on the door, identified themselves and their purpose, and, having heard no reply, proceeded to enter the house through both the back and front doors. Upon entering the residence, they found defendant’s wife and a child. They looked through the rooms and closets of the house in order to ascertain the presence of any other people. They found no one. They did not search for or seize any evidence at that time.
Approximately ten to fifteen minutes later, Lt. Galland arrived at the premises with the search warrant. Thereafter, officers conducted a thorough search of the premises and found: two bags of marijuana; twelve tinfoil packets of 8-14% heroin; a bag containing 15 grams of 17% heroin; a “fix kit” containing syringe and rubber hose; and a scale.
Prior to trial, defendant had made a motion to suppress the evidence of the search on the grounds raised here on appeal. As new evidence became available, this motion was renewed several times, before and during trial, and was denied each time by the trial court.
I
THE SUPPRESSION ISSUE
Defendant asserts three independent grounds in support of his contention that the court below erred in denying his motion to suppress. First, he maintains that the affidavit offered in support of the search warrant was insufficient to demonstrate probable cause. Secondly, he argues that the actions of the three officers in “securing the premises” prior to the arrival of the search warrant was unlawful. Thirdly, defendant insists that the description of his residence in the affidavit and search warrant was insufficient in that it did not particularly describe the premises to be searched. We will address these issues separately.
A. Sufficiency of the affidavit in support of the search warrant.
We note at the outset the somewhat deferential standard of appellate review used to test the sufficiency of affidavits in support of search warrants. Affidavits for search warrants should not be reviewed and tested in a hypertechnical manner. United States v. Ventresca, 380 U.S. 102, 85 S.Ct. 741, 13 L.Ed.2d 684 (1965); State v. Oropeza, 97 Idaho 387, 545 P.2d 475 (1976). A magistrate’s determination of probable cause should be accorded great deference by the appellate court. Spinelli v. United States, 393 U.S. 410, 89 S.Ct. 584, 21 L.Ed.2d 637 (1969); State v. Oropeza, supra. Similarly, such affidavits should be tested by standards less rigorous than those governing the admissibility of evidence at trial. Spineili v. United States, supra.
Keeping the above standards of appellate scrutiny in mind, we turn now to the sufficiency of the affidavit in question. The affidavit, signed by Lt. Galland, was based primarily on two sources of information: a confidential informant and prior surveillances of the defendant conducted by law enforcement officers. The officers had observed Gomez making heroin deliveries in the Boise area on two separate occasions, thirty-nine and forty-five days prior to the issuance of the warrant. On the day before the warrant was issued, the confidential informant had told Lt. Galland that quantities of narcotics could be found at the Gomez residence.
The defendant argues that the information provided by the confidential informant does not meet the two-pronged test articulated by the United States Supreme Court in Aguilar v. Texas, 378 U.S. 108, 84 S.Ct. 1509, 12 L.Ed.2d 723 (1964); further explicated in Spinelli v. United States, supra,, and implemented by this Court in State v. *806Oropeza, supra, and State v. Alger, 100 Idaho 675, 603 P.2d 1009 (1979). The requirements of the test are as follows:
“Although an affidavit may be based on hearsay information and need not reflect the direct personal observations of the affiant, the magistrate must be informed of some of the underlying circumstances from which the informant concluded that the narcotics were where he claimed they were, and some of the underlying circumstances from which the officer concluded that the informant . . . was ‘credible’ or his information ‘reliable’.” Aguilar v. Texas, 378 U.S. at 114, 84 S.Ct. at 1514, 12 L.Ed.2d at 729 (citations omitted).1
Regarding the informant’s tip in the instant case, it is quite clear that the affidavit met the second prong of the Aguilar-Spinelli test, the so-called “veracity prong.” The affidavit states that the confidential informant had proven reliable on no less than six previous occasions, and his information had directly led to the arrest and prosecution of at least five traffickers of narcotics. The affidavit amply demonstrates the informant’s reliability. See, e.g., Jones v. United States, 362 U.S. 257, 80 S.Ct. 725, 4 L.Ed.2d 697 (1960). We also note that “[a] particularly strong showing on one prong may compensate for a weaker showing on the other.” United States v. Smith, 598 F.2d 936, 939-40 (5th Cir. 1979).
However, the informant’s tip does not meet the first prong of the Aguilar-Spinelli test, dubbed the “basis of knowledge” prong. The affiant, Lt. Galland, states that the tipster informed him that “Carlos Gomez had delivered a quantity of heroin through a third party to two subjects from the Burley, Idaho, area; one of those subjects being a female by the name of Janie Ramos and another male subject known as Pete Guzman.” The affidavit does not indicate whether the confidential informant observed the delivery firsthand.2 Nor does it indicate how it was known that the “third party” had acquired the heroin from Gomez. Not only does the affidavit raise the problematic aspect of hearsay, but also hearsay upon hearsay. See State v. Oropeza, supra.
The state admits as much when it states in its brief: “There is no indication in the affidavit ... as to whether the information provided by the confidential informant was based upon the informant’s observation of Carlos Gomez delivering drugs to a third party who subsequently delivered them to Janie Ramos and Pete Guzman.” Therefore, if the affidavit in question were based solely on the anonymous informant’s tip, we would be compelled to hold the search warrant invalid. The tip, by itself, does not meet the Aguilar test, since it lacks the primary factual data required for the magistrate to evaluate the conclusional validity of the informant’s statements. See Stanley v. State, 19 Md.App. 507, 313 A.2d 847, 861 (1974), cert. denied (1974).
The state insists that this defect is not fatal to the affidavit, pointing out that probable cause here is based not only on the informant’s tip, but also on the affiant’s independent knowledge of defendant’s “recent” narcotics trafficking as observed by other law enforcement officers. The state’s argument is roughly based on the following language from Spinelli: “If the tip is found inadequate under Aguilar, the other allegations which corroborate the information contained in the hearsay report should then be considered.” Spinelli v. United States, 393 U.S. at 415, 89 S.Ct. at 588, 21 L.Ed.2d at 643.
*807As noted by Judge Friendly, writing for the 2nd Circuit Court of Appeals, the effect of a defect in the informant’s tip is diminished when the affidavit presents other independently incriminating information:3
“The lesson we draw from all this is that Aguilar applies with full rigor only when the search warrant or the arrest depends solely on the informer’s tip. When a tip not meeting the Aguilar test has generated police investigation and this has developed sufficient corroboration or other ‘probative indications of criminal activity along the lines suggested by the informant,’ see Rebell, The Undisclosed Informant and the Fourth Amendment: A Search for Meaningful Standards, 81 Yale L.J. 703, 715-17 (1972), the tip, even though hot qualifying under Aguilar, may be used to give such additional color as is needed to elevate the information acquired by police observation above the floor required for probable cause.” United States v. Canieso, 470 F.2d 1224, 1231 (2d Cir. 1972) (emphasis in text).
In the instant case, the affidavit of Lt. Galland sets forth “other probative indications of criminal activity.” The affidavit alleges that on two separate occasions the defendant made deliveries of heroin while under surveillance by investigative officers. Police officers are presumed to be reliable sources of information. United States v. Ventresca, 380 U.S. 102, 85 S.Ct. 741, 13 L.Ed.2d 684 (1965); State v. Alger, 100 Idaho 675, 603 P.2d 1009 (1979). The police officers personally observed criminal activity. Under these circumstances, the issue is not really whether these observations sufficiently corroborate the informant’s tip, but rather whether the criminal activity previously observed by the police officers, supported by the Aguilar -defective informant’s tip can support a magistrate’s finding of probable cause.4 See United States v. McNally, 473 F.2d 934, 939-40 (3rd Cir. 1973) (while recognizing that the “tip plus corroboration” approach is fruitless where the informant’s tip sets forth no detail capable of corroboration, the court nonetheless held that “other independently suspect activity” can together with defective tip establish probable cause).
In a recent case, State v. Alger, supra, this Court recognized that direct observations made by police can be combined with an informant’s tip to constitute probable cause, even though the police observation by itself would be insufficient.
“ ‘[DJirect observations, insufficient unto themselves to establish probable cause, may nevertheless be added to trustworthy hearsay, which ... is also insufficient unto itself, so that the combination of incriminatory elements may establish the probable cause which neither alone quite demonstrates.’ Moylan, Hearsay and Probable Cause: An Aguilar and Spinelli *808Primer, 25 Mercer L.Rev. 741, 778-79 (1974).” State v. Alger, 100 Idaho at 678, 603 P.2d at 1112.
Appellant maintains, however, that the prior police observations cannot support a finding of probable cause because such observations took place thirty-nine and forty-five days prior to the issuance of the search warrant. The defendant contends that this “stale” information fails to establish “present” probable cause. It is generally true that “[a]n affidavit must provide facts sufficient to create probable cause for belief that the forbidden articles are within the place to be searched at the time the search warrant is requested.” State v. Oropeza, 97 Idaho at 392, 545 P.2d at 480. Unfortunately, there exists no magical number of days within which information is fresh and after which the information becomes stale. The question must be resolved in light of the circumstances of each case. Id.; Sgro v. United States, 287 U.S. 206, 53 S.Ct. 138, 77 L.Ed. 260 (1932); United States v. Hyde, 574 F.2d 856 (5th Cir. 1978); State v. Ingram, 251 Or. 324, 445 P.2d 503 (1968). See generally Annot., 100 A.L.R.2d 524 (1965).
An important factor in “staleness” analysis is the nature of the criminal conduct. If the affidavit recounts criminal activities of a protracted or continuous nature, a time delay in the sequence of events is of less significance. See United States v. Hyde, supra; United States v. Johnson, 461 F.2d 285 (10th Cir. 1972).
Under appropriate circumstances, some courts have viewed drug trafficking as an inherently continuous activity. Johnson v. State, 14 Md.App. 721, 288 A.2d 622 (Md. App.1972). In Johnson, the lapse of time was twenty-six days. As in the case at bench, there had been two prior observations of drug trafficking by law enforcement personnel. The Johnson court stated that the activities described in the affidavit “seemed to suggest a continuing business in the distribution of narcotics.” Id., 288 A.2d at 628. Cf. United States v. Harris, 482 F.2d 1115, 1119 (3rd Cir. 1973) (“[protracted and continuous activity is inherent in a large-scale narcotics operation”).
In this case, we believe that the two prior heroin deliveries observed by law enforcement officers at least raise the inference that the defendant was engaged in the continuing business of distributing narcotics. It must also be noted that Lt. Galland used the present tense in describing the information provided by the confidential informant.5 Use of the present tense, even by a confidential informant, lends support to a finding of “present” probable cause. See State v. Boudreaux, 304 So.2d 343 (La.1974); State v. Clay, 7 Wash.App. 631, 501 P.2d 603 (1972).
We specifically decline to hold whether the prior observations in this case would by themselves support a finding of probable cause. We hold only that such observations, when coupled with the informant’s information that Gomez currently had in his possession and at his residence quantities of narcotics, raises this affidavit above the floor of probable cause. In so holding, we have taken into consideration the informant’s impressive record as a source of reliable information in the past. We have also considered that, as previously observed, a strong veracity prong may strengthen other areas of weakness in the affidavit. Basically, the prior observations of the police officers suggest a protracted course of criminal activity on the part of the defendant, and the allegations of the confidential informant bring the activities of defendant current and place the evidence to be seized squarely in the defendant’s residence.
We therefore conclude, allowing due deference to the decision of the magistrate in this case, that the prior investigative observations of defendant’s criminal activity, bolstered by the information supplied by a highly reliable informant, are sufficient to support a finding of probable cause.
*809B. Securing the premises.
We next decide whether the initial entry, which was intended to “secure” the Gomez residence, was permissible. Agent Johnson and two other officers had entered the premises ten to fifteen minutes prior to the arrival of Lt. Galland, the defendant, and the search warrant. At the time of the initial entry, Galland and other officers were in downtown Parma, three to four blocks away, arresting the defendant. The arrest, pursuant to warrant, was executed at an auto parts store. When Galland arrived at the defendant’s house a search was conducted and the evidence in question was seized.
Defendant claims the above procedure violated I.C. § 19-4408, and that any evidence seized must be suppressed. We cannot agree.
I.C. § 19-4408 reads as follows:
“19-4408. SERVICE OF WARRANT. —A search warrant may in all cases be served by any of the officers mentioned in its directions, but by no other person, except in aid of the officer on his requiring it, he being present and acting in its execution.”
We fail to see how the act of “securing the premises” in this case violated the terms of the above statute. The statute requires that the warrant be served “by any of the officers mentioned in its directions.” Here, the warrant was directed to “any sheriff, constable, marshal or policeman” in Canyon County. It therefore included Agent Johnson and the two officers who initially entered and “secured the premises.” The statute says nothing about the necessity of the warrant being present upon the initial entry. It requires only the presence of the officer or officers directed to execute it. Granted, the statute does require that the warrant be “served,” which necessarily requires that the warrant be present. However, the statute does not specify whether the service must take place before the search is commenced.
The procedure for service and execution of search warrants is also governed by I.C.R. 41, Idaho’s counterpart to Rule 41 of the Federal Rules of Criminal Procedure. We find the following comment of the United States Supreme Court to be equally applicable here:
“Rule 41(d) does require federal officers to serve upon the person searched a copy of the warrant and a receipt describing the material obtained, but it does not invariably require that this be done before the search takes place.” Katz v. United States, 389 U.S. 347, 355, 88 S.Ct. 507, 513, 19 L.Ed.2d 576, 584 (1967) at n. 16.
Accord, United States v. McKenzie, 446 F.2d 949 (6th Cir. 1971); State v. Wraspir, 20 Wash.App. 626, 581 P.2d 182 (1978).
Several courts have concluded that the fact that the investigative officers initiated a search without the issued but undelivered warrant in their physical possession did not invalidate the search. United States v. Woodring, 444 F.2d 749 (9th Cir. 1971); United States v. Cooper, 421 F.Supp. 804 (W.D.Tenn.1976); State v. Johnson, 240 N.E.2d 574 (Ct.C.P.Ohio 1968). See Mayorga v. People, 178 Colo. 106, 496 P.2d 304 (1972); Williams v. State, 476 S.W.2d 300 (Tex.Cr.App.1972). But see United States v. Seely, 570 F.2d 322 (10th Cir. 1978). In Woodring and Cooper, the searches in question were commenced by agents who had been informed via radio communication that the warrant had indeed been issued. In Cooper, it was IV2 hours after the initiation of the search that the warrant finally arrived. Both courts declined to suppress the evidence.
The above concept is not foreign to Idaho law. Arrest warrants may be executed by officers without the warrant in their possession. I.C.R. 4(c)(3) (renumbered as I.C.R. 4(h)(3), effective July 1, 1980).
Nor has the practice Qf “securing the premises” been condemned by this Court. To the contrary, while we have never explicitly confronted the issue, we have twice commented favorably on the practice.
In State v. Miles, 97 Idaho 396, 545 P.2d 484 (1976), we said that while the officers could not conduct a warrantless search of *810an automobile suspected of containing contraband, they could have posted a guard with the car, thereby securing it, while others went to obtain the warrant.
In State v. Rauch, 99 Idaho 586, 586 P.2d 671 (1978), we affirmed a trial court’s suppression of evidence which was based, among other things, on the police officers’ failure to comply with the Idaho knock and announce statutes, I.C. §§ 19-611 and -4409. The state’s concern in Rauch, which was again expressed in this case, centered around the possibility that the drugs could have been easily destroyed unless the police immediately took action to prevent it. In Rauch, we recognized the legitimacy of the state’s concern but declined to hold that it justified failure to knock and announce pri- or to entry.
“In this case as the trial court explicitly noted, the time frame involved gave probable cause to enter and secure the Rauch premises without a warrant but did not excuse the necessity of complying with Idaho’s ‘knock and announce’ statute. There was no urgency which justified noncompliance with the statute even though there was probable cause to enter and secure the premises.” Id. at 591, 586 P.2d at 676 (emphasis added).
In the instant case, the defendant was arrested in a public place. The officers apparently feared that, given the size of Parma and the location of the arrest, their actions would attract attention and that a phone call to the Gomez residence might enable the occupants to quickly dispose of the drugs. This concern seems reasonable, especially in view of the informant’s allegation that the drugs were possibly stored in the bathroom within ready reach of rapid disposal. In fact, this allegation prompted the magistrate to include a “no-knock” provision in the search warrant.
There is currently a split of authority among the courts concerning the effect of entries intended to secure the premises where no warrant has been issued. Some courts actively condone the practice of securing the premises while the warrant is being obtained. See State v. Broadfoot, 115 Ariz. 537, 566 P.2d 685 (Ariz.1977); State v. Mankel, 27 Ariz.App. 436, 555 P.2d 1124 (Ariz.App.1976). Other courts hold that the initial entry, assuming its constitutional or statutory infirmity, does not taint the second entry and search undertaken pursuant to a valid search warrant. State ex rel. Hyder v. Superior Court of Maricopa County, 114 Ariz. 337, 560 P.2d 1244 (1977); State v. Smith, 112 Ariz. 531, 544 P.2d 213 (1975); People v. Hannah, 183 Colo. 9, 514 P.2d 320 (1973); State v. Fenin, 154 N.J.Super. 282, 381 A.2d 364 (1977). Still others find the initial entry undertaken prior to the issuance of the warrant to be so repugnant as to require suppression of evidence subsequently seized pursuant to a validly issued and executed warrant. United States v. Griffin, 502 F.2d 959 (6th Cir. 1974), cert. denied 419 U.S. 1050, 95 S.Ct. 626, 42 L.Ed.2d 645 (1974); People v. Shuey, 13 Cal.3d 835,120 Cal.Rptr. 83, 533 P.2d 211 (1975); State v. Matsen, 287 Or. 581, 601 P.2d 784 (1979); State v. Bean, 89 Wash.2d 467, 572 P.2d 1102 (1978). However, we need not choose between these conflicting lines of authority. Today we hold only that an entry intended to secure the premises is not improper when undertaken after and with knowledge of the issuance of the warrant, but prior to its arrival at the premises to be searched.
C. The Non-existent House Number.
The defendant’s final attack on the validity of the search is based on an error in the description of the subject premises. The search warrant issued by the magistrate indicated that the house was “identified with the number 204 posted on the front of the house . . . . ” While there is a conflict in the testimony, a preponderance of the evidence indicates that the number did not appear on the house at the time of the search. Defendant insists that this discrepancy invalidates the search warrant, citing State v. Yoder, 96 Idaho 651, 534 P.2d 771 (1975). In Yoder, we held that “[t]he description must be sufficiently clear so that the property to be searched is recognizable from other neighboring properties.” Id. at 653, 534 P.2d at 773. The only distin*811guishable description contained in the Yoder warrant and supporting affidavit was an incorrect house number.
In State v. Hart, 100 Idaho 137, 594 P.2d 647 (1979), we held that a district court erred “in quashing a search warrant where the house to be searched was described by an erroneous house number, but was further identified by additional physical features contained in the warrant.” Id. at 138, 594 P.2d at 648. We think Hart is controlling. See State v. Carlson, 101 Idaho 598, 618 P.2d 776 (1980).
In the instant case, the warrant described the premises to be searched as “a white single-story frame dwelling house located at Route 3, Parma, Idaho, on a road known as Highway 18 or Roswell Boulevard, located in the middle of the block on the east side of the highway between Wendle Street and Park Street, in Canyon County, Idaho, which is under the possession and control of one CARLOS GOMEZ.”
It is immediately clear that the detail in this description surpasses the description in the Yoder warrant. Significantly, the Gomez residence was the only house on the east side of Highway 18 between Wendle and Park Streets. The possibility of a mistaken identification being minimal, we conclude that the description in the warrant is sufficient.
II
Defendant next contends that the trial court erred in limiting his cross examination of Lt. Galland at the suppression hearing. The court did not permit defense counsel to ask Galland whether photographs were taken on the exterior of the house on the day of the search. Defendant also asserts that he was denied due process of law by virtue of the state’s failure to disclose certain photographs taken the day of the search. These photos established that the number “204” did not appear on the front side of the house.
Both of these contentions concern the adequacy and accuracy of the description of the premises in the warrant and supporting affidavit. As we have previously concluded, the description is sufficient apart from any disparity with respect to house numbers.
Ill
We now turn to issues concerning the evidence of defendant’s intent to deliver the narcotics in question. During the trial, the state elicited testimony from one Hendrix, a special agent for the federal Drug Enforcement Administration. The trial court found that Hendrix’s experience and training qualified him as an expert in narcotics investigation and paraphernalia. Defendant does not dispute that finding.
Hendrix’s direct examination culminated in the following exchange:
“Q. Now, based upon your experience, training and education, familiarity with narcotics and narcotics users, Officer Hendricks, do you have an opinion as to whether or not an individual addict would possess 15 grams of heroin for his personal use?
“A. I do not believe so. I have never seen an addict have that quantity for his own use.
“Q. And on what do you base that opinion?
“A. Past cases we have worked involving narcotics traffickers as opposed to an individual addict.”
Defendant objects to this testimony. We see nothing improper in its admission. The above question is a hypothetical one. See G. Bell, Handbook of Evidence for the Idaho Lawyer, at 66-68 (1972). Previous testimony had established that fifteen grams of heroin had been found in defendant’s residence. The factual foundation for the hypothetical question was therefore present in the record. The trial court did not err in permitting Hendrix to express his opinion. See State v. Badger, 96 Idaho 168, 525 P.2d 363 (1974); State v. O’Mealey, 95 Idaho 202, 506 P.2d 99 (1973).
Defendant’s final challenge is directed at the sufficiency of the evidence. He con*812cedes that the record supports the possession conviction, but claims there is no substantial evidence of an “intent to deliver.” The function of this Court in considering evidentiary sufficiency is limited to determining whether there exists substantial and competent evidence. E. g., State v. Kellogg, 100 Idaho 483, 600 P.2d 787 (1979).
In our judgment, the evidence sustains defendant’s conviction. The physical evidence introduced at trial included one packet of fifteen grams of a powdery substance containing 17% heroin, one metal container containing twelve individual tinfoil packets of a powdery substance ranging from 8% to 14% heroin, and scales suitable for weighing. Special agent Hendrix, whose expert qualifications are uncontroverted, testified that not only the quantity, but also the packaging and purity of the heroin seized at defendant’s residence were consistent with sales activities and, conversely, inconsistent with mere use. Agent Hendrix’s testimony was substantially corroborated by the testimony of Lt. Galland. It cannot be said that the evidence is insufficient. See State v. Badger, 96 Idaho 168, 525 P.2d 363 (1974).
The judgment of conviction below is affirmed.
DONALDSON, C. J., McFADDEN, J, and SCOGGIN, J. Pro Tem., concur. BISTLINE, J., dissents.. The Aguilar-Spinelli test is substantially codified in I.C.R. 41(c), which reads in relevant part as follows: “The finding of probable cause shall be based upon substantial evidence, which may be hearsay in whole or in part, provided there is a substantial basis for believing the source of the hearsay to be credible and for believing that there is factual basis for the information furnished.”
. The Aguilar-Spinelli inquiry places a premium on the informant’s personal observation or firsthand knowledge. See State v. Alger, 100 Idaho 675, 603 P.2d 1009 (1979); State v. Archer, 23 Ariz.App. 584, 534 P.2d 1083 (1975); State v. Lemons, 21 Ariz.App. 316, 519 P.2d 69 (1974); State v. Weinberg, 364 So.2d 964 (La. 1978); Laster v. State, 60 Wis.2d 525, 211 N.W.2d 13 (Wis. 1973); 1 W. LaFave, Search & Seizure, A Treatise on the Fourth Amendment, § 3.3(d) (1978).
. Defendant requests that we follow Aguilar and Oropeza and suppress the fruits of the warrant. However, since Aguilar and Oropeza dealt with affidavits based only on information supplied by a confidential informant, they are distinguishable. It is true that in Oropeza, the officer’s supporting affidavit alleged that “surveillance conducted by officers of the City-County Narcotics Division established the above facts to be true.” State v. Oropeza, 97 Idaho at 390, 545 P.2d at 478. However, in view of the conclusory nature of the above allegation, it comes as no surprise that corroboration of an informant’s tip was not an issue in Oropeza.
. Professor LaFave, in his treatise on the fourth amendment, points out that the existence of non-hearsay incriminatory information in the affidavit takes the problem outside the realm of the normal Spineili corroboration problem. “More difficult is the case in which it cannot quite be said that ‘probable cause is established without necessary resort to the hearsay,’ but where this other information standing alone is nonetheless highly suspicious. May it be' said in such a case that the informant’s story, albeit lacking a showing of the basis of knowledge, may be taken into account for the purpose of supplying the ‘little bit more’ which is needed to elevate this other information up to the level of probable cause? The answer is yes.
“A number of the lower court decisions which are based upon the unsound theory that corroboration may remedy an otherwise unestablished basis of knowledge could more readily be explained on the theory just stated.” 1 W. LaFave, Search & Seizure, A Treatise on the Fourth Amendment, § 3.3(e) (1978), at 566-67.
. Lt. Galland’s affidavit stated that “CARLOS GOMEZ has in his custody a quantity of’ illicit drugs. (Emphasis added.)