delivered the opinion of the court:
The defendant, Michael Terrell, was indicted by the grand jury of Kankakee County for the offenses of attempted armed robbery and unlawful use of a weapon. Charles Lott was charged, by the same indictment, with attempted armed robbery and possession of marijuana. The cases were severed for trial and Terrell waived his right to be tried by a jury. At the close of the State’s case in chief, the defendant moved for a directed verdict. The motion was taken under advisement and later denied. The record reveals that a written order was entered on December 28, 1981, finding defendant guilty only of attempted armed robbery, for which he was sentenced to two years’ probation. The appellate court, with one judge dissenting, affirmed the judgment. (110 Ill. App. 3d 1086.) We allowed defendant’s petition for leave to appeal (87 Ill. 2d R. 315(a)).
The sole issue raised on appeal is: Whether the evidence presented is sufficient to establish the essential elements of the offense of attempted armed robbery.
The evidence revealed that on August 7, 1980, at approximately 6:15 a.m., an anonymous telephone call was received by the Kankakee city police. The caller stated that two men, armed with guns, were hiding behind a service station. This report was dispatched and was responded to by Officer Whitehead in one patrol car, and Officers Pepin and Rokus, who were patrolling the area, in another car.
A diagram, entered into evidence, shows that the service station is located on the southwest corner of Er-zinger and Maple streets. The first building south of the station, facing Maple Street, is a construction company. Further south is a tool company. To the rear of the buildings is a large grassy lot which extends to an alley running parallel to the buildings.
Officer Whitehead arrived at the scene within minutes of the radio dispatch and only seconds before Officers Rokus and Pepin. Whitehead pulled into the alley and onto the empty lot behind the station, where he immediately observed a man, crouched in the weeds, 20 to 30 feet from the station. As the officer got out of his car, the defendant, who he saw carrying a gun, jumped up from the weeds, ran towards the fence, climbed to the other side and proceeded south down Maple Street. Officer Whitehead testified that the defendant disposed of the gun sometime before he scaled the fence, although he could not remember seeing it being dropped.
Twelve to fifteen minutes after he was initially observed, Officer Pepin discovered the defendant hiding in the weeds behind the tool company, approximately 280 feet from the service station. The defendant had removed his shirt and was lying on it. A black nylon stocking with a knot in the end of it was found in his pocket. Although the defendant claimed that he was going to the gas station to buy cigarettes, the officer found no money on defendant’s person. Officer Whitehead, later, positively identified the defendant as the man he had observed with the gun.
As Officers Rokus and Pepin approached the scene, they observed Whitehead’s car and a subject wearing a yellow shirt, later identified as Charles Lott, going over the fence. Rokus apprehended Lott, three minutes later, in the rear of the construction company, approximately 180 feet from the service station. Both Rokus and Pepin identified Lott as the man they had observed scaling the fence. Officer Pepin searched Lott’s pants, finding one bag of cannabis and a black stocking with a knot tied on the end. During his search for the second suspect, Officer Pepin found a fully loaded revolver lying on the ground, six inches from the fence. It is unclear from the record if the station was open at the time the officers arrived on the scene. Officer Whitehead did notice, however, that the station was open at some time during his search of the area.
The defendant maintains that the State’s evidence is insufficient to establish the two essential elements of the offense of attempt. Section 8 — 4(a) of the Criminal Code of 1961 (Ill. Rev. Stat. 1979, ch. 38, par. 8 — 4(a)) provides:
“A person commits an attempt when, with intent to commit a specific offense, he does any act which constitutes a substantial step toward the commission of that offense.” (Emphasis added.)
Section 18 — 2(a) of the Criminal Code of 1961 (Ill. Rev. Stat. 1979, ch. 38, par. 18 — 2(a)) provides:
“A person commits armed robbery when he or she [takes property from the person or presence of another by the use of force or by threatening imminent use of force] while he or she carries on or about his or her person, or is otherwise armed with a dangerous weapon.”
We find that the facts and circumstances of this case are sufficient to prove that the defendant possessed the requisite intent to commit a specific armed robbery and that he took a substantial step toward the commission of that armed robbery. For the reasons to follow, therefore, we affirm the judgment of the appellate court.
It is well established that, to obtain a conviction for attempt, the State must prove that the defendant intended to commit a specific offense. (People v. Stroner (1983), 96 Ill. 2d 204, 211; People v. Trinkle (1977), 68 Ill. 2d 198, 202; People v. Viser (1975), 62 Ill. 2d 568, 581.) As the court stated in Viser, “[tjhere is no such criminal offense as an attempt to achieve an unintended result.” (62 Ill. 2d 568, 581.) The intent to commit a criminal offense need not be expressed, but may be inferred from, the conduct of the defendant and the surrounding circumstances. (People v. Mulcahey (1978), 72 Ill. 2d 282.) Thus, in Mulcahey, where the defendant was convicted of attempted armed robbery, the court was able to infer the requisite intent to take money from a victim by force, although no specific demand for money had been made.
While the defendant, in the instant case, does not deny the presence of “some” criminal intent, he maintains that the evidence fails to “imply a design to commit an armed robbery at the station.” He suggests a list of alternative targets and offenses which includes the crime of burglary as opposed to armed robbery. In addition, he finds it significant that the State failed to establish that the gas station was open when he was initially discovered.
We find this argument unpersuasive. It is unreasonable to expect a trier of fact to infer intent to commit burglary, rather than armed robbery when confronted with a suspect who was seen carrying a loaded revolver and in possession of a ladies’ stocking but no burglary tools. In addition, the trial court could reasonably infer that the service station was the object of defendant’s plan. The defendant was observed in close proximity to the station, by Officer Whitehead, as he arrived on the scene. This observation was in conformity with the initial tip from the telephone caller who specifically indicated that the suspects were hiding behind the service station. As for the victim necessary for an armed robbery, the trier of fact may reasonably have inferred that the defendant was awaiting the attendant’s arrival before taking the final step in his plan. Furthermore, although armed robbery requires a victim, “[i]t [is] not *** a defense to a charge of attempt that because of a misapprehension of the circumstances it would have been impossible for the accused to commit the offense attempted.” (Ill. Rev. Stat. 1979, ch. 38, par. 8 — 4(b).) It is not a defense to the charge of attempted armed robbery, therefore, to take a substantial step toward the commission of the armed robbery only to find the victim, the attendant, not yet present.
The evidence presented to the trier of fact, in this case, revealed a defendant who had concealed himself in the weeds in close proximity to a service station, which was about to open, while in possession of a stocking mask and a fully loaded revolver. In further support of an inference of criminal intent, defendant’s efforts to elude the police as well as his weak excuse for his presence at the scene, could also be properly considered. (People v. Harris (1972), 52 Ill. 2d 558, 561.) Faced with these facts, we find it incredulous that defendant had any intent other than the armed robbery of the service station.
We turn next to what has been described as “one of the most troublesome problems” in the area of inchoate offenses: “when preparation to commit an offense ceases and perpetration of the offense [attempt] begins.” (Ill. Ann. Stat., ch. 38, par. 8 — 4(a), Committee Comments, at 512 (Smith-Hurd 1972).) Answering this question requires an analysis of the second statutory element of the offense of attempt — “any act which constitutes a substantial step toward the commission of that offense.” (Ill. Rev. Stat. 1979, ch. 38, par. 8 — 4(a).) Although it is not necessary that a defendant complete the last proximate act in order to be convicted of attempt, our cases have held that mere preparation is not a substantial step. (People v. Elmore (1971), 50 Ill. 2d 10, 12; People v. Woods (1962), 24 Ill. 2d 154, 158.) It would be an impossible task to compile a definitive list of acts which, if performed, constitute a substantial step toward the commission of every crime. Such a determination can only be accomplished by evaluating the facts and circumstances of the particular case. (People v. Wallace (1974), 57 Ill. 2d 285, 292.) This is not to suggest, however, that analysis of cases which have defined “substantial step” cannot provide some guidance.
In affirming the decision of the trial court, the appellate court, in this case, relied on People v. Burleson (1977), 50 Ill. App. 3d 629. When placing the facts in this case on the continuum between preparation and perpetration, comparison with the facts in Burleson becomes useful. In Burleson, the defendant and his accomplice had approached a bank while “.in possession of a shotgun, suitcase and disguises which were in place.” (50 Ill. App. 3d 629, 633.) Only the quick action of a man inside the bank, who bolted the door as the perpetrators approached, prevented completion of the offense. The court found that the defendant in Burleson had taken a substantial step toward the armed robbery of the bank. The defendant, in the instant case, did not yet have his mask on nor had he arrived at the station’s front door. It would be unreasonable to believe, however, that the defendant’s actions did not place him in “ ‘dangerous proximity to success.’ ” People v. Paluch (1966), 78 Ill. App. 2d 356, 360, quoting Hyde v. United States (1912), 225 U.S. 347, 388, 56 L. Ed. 1114, 1134, 32 S. Ct. 793, 810 (Holmes, J., dissenting).
A later appellate court decision, People v. Reyes (1981), 102 Ill. App. 3d 820, provides further comparison with the facts of the instant case. The defendants in Reyes were found guilty of attempted armed robbery. While in possession of a rifle, they approached, but did not enter, a drugstore. The intended victims were inside the store. Shortly after the defendants’ arrival on the scene, several patrons walked out of the drugstore. Reyes and his codefendant began to run while, at the same time, the codefendant fired his rifle. They were arrested in a nearby school yard a short time later. In a statement, Reyes said that the plan was to rob the victims as they exited the drugstore.
Reyes maintained that he could not be found guilty of attempted armed robbery because he had never entered the drugstore. In rejecting that argument, the court noted that, by Reyes’ own admission, his plan did not contemplate entry into the building. Relying on Burleson, the court went on to say that when the victim of an intended armed robbery is within a building, “entry into that building is not required for a finding of attempt armed robbery. *** Burleson stands for the principle that a substantial step has been taken when an actor possesses the materials necessary to carry out the crime, at or near the place contemplated for its commission.” (102 Ill. App. 3d 820, 835.) Like the defendants in Burleson and Reyes, the defendant, in the case at bar, was in possession of the materials necessary to carry out an armed robbery and was near the place contemplated for its commission. He was armed with a loaded revolver, a disguise and the assistance of an accomplice, whose presence and identical disguise indicated a prearranged plan. He was lying in wait, only 25 to 30 feet from his target, with gun in hand. It was only the arrival of the police which caused him to abandon his plan.
When defining “attempt” it becomes problematic deciding when to allow the police to intervene in an unfolding course of criminal conduct. While caution must be exercised to avoid punishment for inconclusive acts, prevention of an intended crime is necessary. (Wechsler, Jones & Korn, The Treatment of Inchoate Crimes in the Model Penal Code of the American Law Institute: Attempt, Solicitation & Conspiracy, 61 Colum. L. Rev. 571, 572 (1961).) The defendants in Burleson, Reyes and the case at bar were involved in crimes which posed a serious threat of great bodily harm to the victim. It should not be necessary to subject victims to face to face confrontation with a lethal weapon in order to make a positive finding of the essential element of a substantial step.
The Model Penal Code has set forth a list of acts which may be considered to be a substantial step, when strongly corroborative of the actor’s criminal purpose. The appellate court, in this case, found the defendant’s conduct to be described by several acts on the list. These were:
“(a) lying in wait, searching for or following the contemplated victim of the crime;
(b.) * * *
(c) reconnoitering the place contemplated for the commission of the crime;
(d.) * * *
(e) possession of materials to be employed in the commission of the crime, which are specially designed for such unlawful use or which can serve no lawful purpose of the actor under the circumstances;
(f) possession, collection or fabrication of materials to be employed in the commission of the crime, at or near the place contemplated for its commission, where such possession, collection or fabrication serves no lawful purpose of the actor under the circumstances;
(g) ***.” (Model Penal Code sec. 5.01(2) (Proposed Official Draft 1963).)
A comparison of the categories of acts included on this list with the specific actions of the defendant gives further support to a finding of a substantial step.
The record reflects no error which requires reversal. We find the evidence presented in this case is sufficient to establish, beyond a reasonable doubt, defendant’s intent to commit armed robbery of an individual within the service station and that he took a substantial step toward the commission of the armed robbery. The judgment of the appellate court is affirmed.
Judgment affirmed.