Convicted by a Superior Court jury of possession of marihuana, cocaine and LSD with intent to dis*766tribute, the defendant appeals, claiming that his motion to suppress evidence was wrongly denied and that the evidence adduced at trial was not sufficient to support the convictions. We affirm.
1. The affidavit. The question presented by the denial of the defendant’s suppression motion is whether the affidavit of a police officer provided “a substantial basis for concluding that any of the articles described in the warrant are probably in the place to be searched.” Commonwealth v. Upton, 394 Mass. 363, 370 (1985). The necessary predicate is probable cause to believe that at the time of the search evidence of criminal activity would be found at the premises searched. Commonwealth v. Reddington, 395 Mass. 315, 323 (1985).
The affidavit, dated May 1, 1989, recites that on April 29, 1989, Mr. and Mrs. James McCalab, owners of a seven-family apartment house in Pittsfield, told the affiant, a police officer with considerable experience in drug investigations, that “they feel that their tenant in Apt. #5, Richard Monterosso, was dealing drugs from the apartment. [They said] . . . they felt that way because of the inordinate amount of traffic in and out of Monterosso’s apartment.” Mrs. McCalab said that on April 23 she saw fifteen to twenty people enter and exit the apartment in a one and one-half hour period. Mr. McCalab stated that on April 28 and April 29 he saw at least twelve to fifteen people on each day enter and leave Monterosso’s apartment after a visit of less than five minutes. The McCalabs also reported that on some occasions the visitors left the area in cars, occupied by others, which had been kept running outside the apartment housé.
The next paragraph of the affidavit recites that “[w]ithin the last 3 days I contacted a credible and reliable informant [CR1] who has made controlled buys of controlled substances for me in the past. As a result of these controlled buys search warrants were obtained and seizures of controlled substances and arrests of offenders occurred.” After a failed attempt at making a controlled buy from the defendant, CR1 reported to the affiant that, while “talking to Richard Monterosso,” the informant “saw a trail of smoke that *767was definitely marijuana smoke exit the door of [ajpartment 5 . ...” He suggested to the affiant that he “would be able to smell the marijuana smoke if [he] went up in the hallway . . . and stood in front of door #5.”
According to the affidavit, the affiant and a fellow officer, Sergeant Sciola, drove CR1 back to his house, and “Sgt. Sci-ola and myself then went into [the apartment house] and followed a distinct odor trail of marijuana to the door of apartment §5, the home of Richard Monterosso.” From their past experience, the police officers recognized the smell of burning marihuana.
The affidavit gave a brief description of the apartment house, noting that there were three apartments on the second floor of the house, one of which was apartment #5, and four apartments on the first floor. Also, the affidavit described the “long and constant record of arrests [of Monterosso] for distributing controlled substances.” The affidavit cited arrests on June 7, 1987, September 30, 1987, and October 12, 1987, as a result of which the defendant pleaded guilty to various marihuana and cocaine distribution crimes and spent a period of time in the Berkshire County house of correction. Finally, the circumstances and unusual amount of short term traffic reported by the McCalabs, coupled with Monterosso’s record of recent convictions, led the affiant to state in a report incorporated in the affidavit: “This would show that [the defendant] definitely has a history and a[n] up-to-date continuous record of selling controlled substances” (emphasis supplied). The search warrant issued on May 1, 1989, and was executed on May 5, 1989.
The substantive components of the affidavit consist of the information conveyed by the McCalabs and CR1, the detection of the odor of marihuana by the affiant and his colleague, the report of the defendant’s criminal record and the conclusions drawn by the affiant. Where the question of legal sufficiency is a close one, its resolution is often dependent, as the court’s division well illustrates, upon the degree of deference given to the magisterial determination of probable cause and whether the analysis focuses primarily on the affidavit as *768an organic whole or on its component parts. A fundamental principle of search warrant review is that “[t]he sufficiency of the affidavit is to be decided on the basis of a consideration of all of its allegations as a whole, and not by first dissecting it and then subjecting each resulting fragment to a hyper technical test of its sufficiency standing alone.” Commonwealth v. Stewart, 358 Mass. 747, 751 (1971). Moreover, when viewed as parts of a panoramic presentation, and not in isolation, the components of an affidavit may tend to buttress rather than undermine a determination of probable cause.
A logical and commonsense reading of the affidavit leads to the conclusion that marihuana was present in the defendant’s apartment within two days of the date of the affidavit. During that period, not only did CR1 report seeing marihuana smoke emerging from the defendant’s apartment but the affiant and another police officer also traced the odor of marihuana to the door of that apartment. For CRl’s affidavit information to be given credence, his veracity must be established under the familiar two-pronged test of Aguilar v. Texas, 378 U.S. 108 (1964), and Spinelli v. United States, 393 U.S. 410 (1969). Commonwealth v. Upton, 394 Mass. 363, 373-376 (1985). While it is debatable whether CRl’s past successful participation in controlled buys establishes his credibility,2 the underlying circumstances of his report of marihuana smoke reasonably support the conclusion that his information was reliable.3 The affidavit informs us that the police officers supervised the attempt and watched the informant enter and leave the building which housed apartment #5. It is reasonable to conclude that the informant, knowing that the police were so proximately positioned and, *769therefore, perhaps able to check his information, was unlikely to report falsely. Close supervision of an informant coupled with police involvement in his investigative activities substantially reduce the risk of falsehood. See 1 LaFave, Search & Seizure §3.3(f), at 686-687 (2d ed. 1987). Moreover, the detection of the odor of marihuana at the door of the defendant’s apartment, in itself evidence of an incriminating nature, gives corroborating effect to the informant’s observations and his prediction, reported in the affidavit, that the affiant “would be able to smell the marijuana smoke if [he] went up in the hallway . . . and stood in front of door #5.” That the police officers’ detection of evidence of marihuana outside of apartment #5 does not preclude possible explanation other than its presence within the apartment is of no moment. Although its information is “susceptible of other interpretations, . . . the affidavit must only establish probable cause, not proof beyond a reasonable doubt.” Commonwealth v. Byfield, 413 Mass. 426, 431 (1992).
The statements of the McCalabs, standing alone, would not be sufficient to establish probable cause, even with the additional weight accorded information from identified informants. See Commonwealth v. Grzembski, 393 Mass. 516, 522 (1984). However, that information takes on added significance when combined with the affidavit report of the defendant’s having been arrested on three occasions for selling marihuana and cocaine and pleading guilty to all three charges less than nineteen months prior to the date of the affidavit. “The record of prior convictions [may be] used as a factor because the convictions were recent, and the crimes sufficiently similar to be relevant on the determination of probable cause.” Commonwealth v. Germain, 396 Mass. 413, 418 n.7 (1985) (approximately eighteen months between the defendant’s sentencing, for crimes similar to that described in the affidavit, and date of the affidavit).
The McCalabs’ observations of continuing activity, viewed in the context of the defendant’s recent criminal record for drug crimes and buttressed by the weight which should be given to the special insight of an experienced police officer, *770see Commonwealth v. Taglieri, 378 Mass. 196, 199, cert, denied, 444 U.S. 937 (1979), and by affidavit evidence of the presence of marihuana in apartment #5 sometime after April 29, 1989, sufficiently establish the probability that illegal drugs would be found in that apartment.
Judicial concern for preserving and strengthening constitutional protections is not served by “[a] grudging or negative attitude . . . toward warrants,” United States v. Ventresca, 380 U.S. 102, 108 (1965), nor by disregard of well-established principles urging reviewing courts to “give great deference to the magistrate’s determination of probable cause,” Commonwealth v. Upton, 394 Mass. at 377, to “adopt a commonsense approach in reviewing searches under the Fourth Amendment as well as under art. 14,” Commonwealth v. Byfield, 413 Mass. at 430 n.6, and to recognize that “the resolution of doubtful or marginal cases in this area should be largely determined by the preference to be accorded to warrants.” United States v. Ventresca, supra at 109.
2. Sufficiency of the evidence. The defendant argues that the small amounts of marihuana, cocaine and LSD found in the defendant’s control as a result of the search of his apartment are sufficient only for conviction of possession and do not support inferences of intent to distribute. He points to police testimony that the amounts found were consistent with personal use as well as distribution and to the principle that a guilty verdict may not be upheld where the evidence tends equally to support guilt and innocence. See Commonwealth v. Eramo, 377 Mass. 912, 913 (1979); Commonwealth v. Ferguson, 384 Mass. 13, 19 (1981). The argument fails to recognize the weight which a jury reasonably could have given to (1) physical evidence of distribution found in the defendant’s apartment including a hand-held scale, described in testimony as being of a type associated with the weighing and selling of marihuana, three one-pound bags with mari*771huana residue in them and an “OZ”4 sheet commonly used to record drug transactions; (2) a police officer’s testimony of his observation of several persons making short term visits to the defendant’s apartment shortly before the search visits which he connected to the selling of drugs; (3) the defendant’s admissions to police officers of selling small amounts of marihuana and cocaine to his friends and to the price he received for LSD; and (4) his admission that the drugs found in his apartment were to be used the next night at a party with his friends. The cumulative force of this trial evidence and the reasonable inferences which could be drawn from it amply satisfy the familiar directed verdict standard recited in Commonwealth v. Latimore, 378 Mass. 671, 676-678 (1979).
Judgments affirmed.
See State v. Maddasion, 130 Ariz. 306, 308 (1981); 1 LaFave, Search & Seizure §3.3(b), at 631 (2d ed. 1987).
At issue here is whether the requirements of either the credibility or reliability “spurs” of the veracity “prong” of the Aguilar-Spinelli test have been met. If an informant’s track record does not establish his credibility, the question posed is whether a conclusion that his information was reliable is supported by other evidence in the affidavit or by police corroboration. See Smith, Criminal Practice & Procedure §§ 211-215 (2d ed. 1983).
The OZ sheet was described at trial by a prosecution witness as containing names of persons, dollar amounts owed and, in one instance, the words “twenty pills.”