Appellant, William Harvey Mitchell, and a co-defendant, Gordon R. Johnson, were each charged with separate counts of burglary,1 criminal attempt,2 and conspiracy.3 Following a joint jury trial, Johnson4 was found guilty of all charges while appellant was acquitted of burglary and criminal *148attempt but convicted of conspiracy. Appellant maintains, inter alia, that the evidence was insufficient5 to sustain his conviction on the charge of conspiracy.
“[T]he test of the sufficiency of the evidence — irrespective of whether it is direct or circumstantial, or both — is whether, accepting as true all the evidence and all reasonable inferences therefrom, upon which if believed the jury could properly have based its verdict, it is sufficient in law to prove beyond a reasonable doubt that the defendant is guilty of the crime or crimes of which he has been convicted.” Commonwealth v. Frye, 433 Pa. 473, 481, 252 A.2d 580, 584 (1969). Moreover, it is well settled that the Commonwealth, as verdict winner, is entitled to have the evidence considered in a light most favorable to it. Commonwealth v. Long, 460 Pa. 461, 333 A.2d 865 (1975).
So viewed, the record discloses the following. On the evening of March 29, 1976, at approximately 11:31 P.M., two officers of the Easton Police Department responded to a silent burglar alarm which had been activated at the Wolf Elementary School. As the officers approached the school by automobile they observed appellant and Johnson emerging from the school grounds. Both men identified themselves upon being stopped by the officers. Appellant informed the police they were taking a short cut. The men were then released and the officers proceeded to the school where they discovered a broken window at the rear of the building. Further investigation inside the school revealed *149that several thousand dollars worth of school equipment, including some television sets, had been placed near an unlocked, outside door on a first floor landing of the building. The school custodian testified that he had locked this door at approximately 7:00 o’clock that evening and that the building was secure at that time. A supervisor testified that it would take two men to carry one of the larger TV sets and that it would require about forty-five minutes to one hour to stack all of the items near the door. A fingerprint found on one of the television sets was identified as belonging to Johnson.
The testimony of various other witnesses, both for the prosecution and for the defense, established that appellant and Johnson had been seen together at a basketball game at the local high school earlier that evening from approximately 7:30 P.M. to 10:30 P.M. It was further established that it would take five to ten minutes to drive from the high school to the site of the crime. The investigating officers stated that they arrived at the school grounds within a “matter of seconds” of the 11:31 P.M. call notifying them that the silent alarm had been triggered.6 Upon arrival, as previously noted, they saw appellant and Johnson coming out of a driveway or alley leading from the school area. Appellant and Johnson were also observed together one hour after their encounter with the police. Although appellant did not testify, Johnson took the stand and stated that after the basketball game he and appellant, accompanied by two women they had escorted to the game, left the high school and drove to Phillipsburg to take one of the women home. The two men and the remaining woman then proceeded to a tavern near the elementary school. At about 11:15 P.M. Johnson and appellant, in accordance with a previous arrangement, walked outside the bar to await the arrival of Johnson’s sister in order to return the car which Johnson had borrowed from her earlier that day. When she arrived, at approximately 11:20 P.M., she informed her brother that her *150other car was not operating properly and she had parked it in a nearby public parking lot.
Johnson and appellant agreed to go over and check the car, whereupon they began walking to the parking lot which was located approximately one block from the scene of the crime. As they were walking down a road adjacent to the school, they were stopped by the police. Five witnesses substantially corroborated Johnson’s account of his and appellant’s activities during the time period in which the crime occurred.
“To sustain a conviction, the facts and circumstances which the Commonwealth prove must be such that every essential element of the crime is established beyond a reasonable doubt. Although the Commonwealth does not have to establish guilt to a mathematical certainty, and may in the proper case rely wholly on circumstantial evidence, the conviction must be based on more than mere suspicion or conjecture.” (Citations omitted.) Commonwealth v. Roscioli, 454 Pa. 59, 62, 309 A.2d 396, 398 (1973).
In relevant part, the Crimes Code, supra, § 903(a), states:
“A person is guilty of conspiracy with another person or persons to commit a crime if with the intent or promoting or facilitating its commission he:
(1) agrees with such other person or persons that they or one or more of them will engage in conduct which constitutes such crime or an attempt or solicitation to commit such crime; or
(2) agrees to aid such other person or persons in the planning or commission of such crime or of an attempt or solicitation to commit such crime.”
The essence of any conspiracy is a common understanding. Commonwealth v. Holguin, 254 Pa.Super. 295, 385 A.2d 1346 (1978); Commonwealth v. Yobbagy, 410 Pa. 172, 188 A.2d 750 (1963). There must be evidence of an agreement to commit an unlawful act. Commonwealth v. Adams, 254 Pa.Super. 62, 385 A.2d 525 (1978). However, “while more *151than mere association must be shown, ‘[a] conspiracy may be inferentially established by showing the relation, conduct or circumstances of the parties, and the overt acts on the part of co-conspirators have uniformly been held competent to prove that a corrupt confederation has in fact been formed.” Commonwealth v. Roux, 465 Pa. 482, 488, 350 A.2d 867, 870 (1976), quoting from Commonwealth v. Horvath, 187 Pa.Super. 206, 211, 144 A.2d 489, 492 (1958).
Instantly, appellant asserts that his conviction cannot stand because mere presence at the scene of the crime is insufficient to establish guilt. See, Commonwealth v. Garrett, 423 Pa. 8, 222 A.2d 902 (1966). The Commonwealth, on the other hand, contends the evidence shows much more than appellant’s mere presence at the scene. Specifically, the Commonwealth argues that the evidence established Johnson’s guilt since a fingerprint of his was found on one of the TV sets and because he was observed in the vicinity of the crime within moments after the silent alarm had been activated. The Commonwealth then proceeds to argue that once it is determined that Johnson was one of the burglars, then the fact that Johnson and appellant were virtually in continuous company during the night in question justifies the inference that appellant was a co-conspirator in the crime.
The Commonwealth’s evidence was insufficient, as a matter of law, to conclude beyond a reasonable doubt that appellant was part of a conspiracy to burglarize the school. The record, read in the light most favorable to the Commonwealth, merely establishes appellant’s association with Johnson on the night of the crime and their presence in the vicinity of the crime immediately after its occurrence.7 Cf. Commonwealth v. Garrett, supra. The testimony, however, is devoid of any indication that appellant counseled or par*152ticipated in the burglary. See Commonwealth v. Fields, 460 Pa. 316, 333 A.2d 745 (1975). Such a conclusion would be sheer conjecture. To infer appellant’s complicity on the basis of his companionship with Johnson, would be tantamount to determining guilt by association. See Commonwealth v. Cox, 460 Pa. 566, 333 A.2d 917 (1975). Under the circumstances, the Commonwealth’s proof left too much to speculation and conjecture. See Commonwealth v. Finley, 477 Pa. 382, 383 A.2d 1259 (1978).
Reverse the judgment of sentence and appellant is discharged.
WATKINS and HOFFMAN, JJ., join in this opinion. SPAETH, J., files a concurring and dissenting opinion. PRICE, J., files a dissenting statement. VAN der VOORT, J., files a dissenting opinion. JACOBS, J., did not participate in the consideration or decision of this case.. The Crimes Code, Act of December 6, 1972, P.L. 1482, No. 334, 18 Pa.C.S. § 3502.
. The Crimes Code, supra; 18 Pa.C.S. § 901.
. The Crimes Code, supra; 18 Pa.C.S. § 903.
. Johnson is not a party to this appeal.
. Appellant presents this contention in terms of whether the trial judge erred in refusing to grant his demurrer to the evidence. However, appellant did not rest following this adverse ruling but proceeded to present evidence in his defense and, therefore, the correctness of this ruling has not been preserved for review. Commonwealth v. Warren, 475 Pa. 31, 379 A.2d 561 (1977); Commonwealth v. Ilgenfritz, 466 Pa. 345, 353 A.2d 387 (1976). “We have chosen, nevertheless, to treat the question as if properly framed, namely, whether the trial court erred in refusing [appellant’s] motion in arrest of judgment. In doing so, of course, we consider all of the evidence, not only that contained in the Commonwealth’s case in chief.” (Citations omitted.) Commonwealth v. Ilgenfritz, supra, 466 Pa. at 347-48, 353 A.2d at 388-389 n.*. See also, Commonwealth v. Duncan, 473 Pa. 62, 373 A.2d 1051 (1977); Commonwealth v. Warren, supra.
. The silent alarm at the school is triggered when sensors in the building register motion and the police department is then immediately notified via automatic telephone transmission.
. It must be emphasized that although the investigating detective lifted numerous latent fingerprints at the scene, none of the prints were appellant’s. Indeed, the Commonwealth’s expert witness could only identify one partial print as that of Johnson’s, and there was no testimony as to when that print had been impressed. See Commonwealth v. Cichy, 227 Pa.Super. 480, 323 A.2d 817 (1974).