delivered the Opinion of the Court.
The prosecution has filed this interlocutory appeal pursuant to C.A.R. 4.1 challenging an order of the Mesa County District Court suppressing physical evidence. Grand Junction police officers discovered the evidence after they stopped the defendant as he was driving a car down an alleyway. The trial court concluded that *191the officers lacked reasonable suspicion to justify the stop. The trial court, therefore, suppressed evidence seized during the subsequent consensual search of the car the defendant was driving. We affirm the trial court’s order and remand the case for further proceedings.
I.
On July 5, 1989, Officer Mark Angelo of the Grand Junction Police Department received information from an anonymous call to Crime Stoppers.1 The caller said that a person named Manuel Ramon Diaz would be leaving the apartment area in the 300 block of Chipeta and driving away in a car parked in the alley. The caller described the car as a brown Toyota or a brown station wagon with license plate UHC788. The caller said that Diaz would be leaving at approximately 1:00 p.m. on that day and that there would be approximately half an ounce of cocaine under the car’s hood in the engine compartment.
Officer Angelo relayed this information to Officer John Zen. Officers Zen, Booth and Callow then drove past the 300 block of Chipeta and saw a brown station wagon with license plate UHC788 parked behind some apartments in that block. They waited nearby in a car. At 1:10 p.m. they saw a man, who was later identified as Manuel Diaz Garcia, also known as Manuel Ramon Diaz, enter the brown station wagon and drive down the alley. The officers then drove their car into the alley and intercepted the defendant’s vehicle.
The officers got out of their car. Officer Zen identified himself as a police officer, and the defendant and a woman who was with him got out of the brown station wagon. In response to questioning, the defendant stated that his name was Manuel Diaz, that the ear belonged to someone named Sonny, and that there were no drugs in the car. Officer Zen then requested and received permission from the defendant to search the car.2
The officers found approximately half an ounce of cocaine under the hood of the car. The trial court granted the defendant’s motion to suppress this evidence based on its conclusion that the cocaine was seized during a constitutionally impermissible stop. The prosecution now appeals.
II.
The prosecution argues that the initial stop of the defendant was a valid investigatory stop authorized by Terry v. Ohio, 392 U.S. 1, 88 S.Ct. 1868, 20 L.Ed.2d 889 (1968), and Stone v. People, 174 Colo. 504, 485 P.2d 495 (1971). We disagree.
Under both the United States Constitution 3 and the Colorado Constitution4 a police officer may stop a person for investigatory purposes under narrowly defined circumstances without having probable cause to arrest the person. See Terry, 392 U.S. at 30, 88 S.Ct. at 1884; People v. Schreyer, 640 P.2d 1147, 1149 (Colo.1982); Stone, 174 Colo. at 508, 485 P.2d at 497. For the stop to be constitutionally valid: “(1) there must be an articulable and specific basis in fact for suspecting that criminal activity has taken place, is in progress, or is about to occur; (2) the purpose of the intrusion must be reasonable; and (3) the scope and character of the intrusion must be reasonably related to its purpose.” People v. Contreras, 780 P.2d 552, 555 (Colo.1989); accord People v. Ratcliff, 778 P.2d 1371, 1376 (Colo.1989).
The issue in this case centers on the first of these three criteria. Before making an investigatory stop, an officer must *192reasonably suspect that an individual is engaged in, has engaged in or is about to engage in criminal conduct. Terry, 392 U.S. at 30-31, 88 S.Ct. at 1884-85; Ratcliff, 778 P.2d at 1376; Stone, 174 Colo. at 509, 485 P.2d at 497. We have required that an officer’s suspicion have “an articulable and specific basis in fact.” People v. Savage, 698 P.2d 1330, 1334 (Colo.1985). The question is “whether there were specific and articulable facts known to the officer, which taken together with rational inferences from these facts, created a reasonable suspicion of criminal activity to justify the intrusion into the defendant’s personal security.” People v. Thomas, 660 P.2d 1272, 1274 (Colo.1983). In determining whether reasonable suspicion existed, we must look to the totality of circumstances. Contreras, 780 P.2d at 555; People v. Bell, 698 P.2d 269, 272 (Colo.1985).
An anonymous tip, by itself, lacks indicia of reliability sufficient to establish reasonable suspicion. Contreras, 780 P.2d at 555; see also People v. McPherson, 191 Colo. 81, 85, 550 P.2d 311, 315 (1976). An anonymous tip together with corroborating observations, however, may provide a specific and articulable basis in fact to suspect that an individual is engaging in criminal conduct. Contreras, 780 P.2d at 555. In some circumstances the verification of seemingly innocent details contained in a tip from an anonymous informant can be sufficient to supply the requisite corroboration. See People v. Villiard, 679 P.2d 593 (1984); cf. Illinois v. Gates, 462 U.S. 213, 103 S.Ct. 2317, 76 L.Ed.2d 527 (1983) (evaluating sufficiency of affidavit for search warrant to establish probable cause).
Applying these standards, the trial court determined that the officers lacked reasonable suspicion to justify stopping the defendant. We conclude that the record supports the trial court’s ruling.
The tip upon which the investigatory stop was based was completely anonymous. The caller did not provide his or her name and had no known prior record of providing reliable information. The total anonymity of the informant distinguishes this case from People v. Lucero, 182 Colo. 39, 511 P.2d 468 (1973). In Lucero, unidentified informants at the scene of an armed robbery spoke to police officers in person and described the getaway vehicle. Based on this description, officers stopped the vehicle and ultimately arrested the defendant. In upholding the validity of the stop, we stated that “we consider a group of unidentified citizen informants who describe a getaway vehicle in response to an on the scene police investigation to possess sufficient reliability to give rise to reasonable cause to stop the described car for investigatory purposes.” Id. at 43, 511 P.2d at 470.
This case is also distinguishable from Adams v. Williams, 407 U.S. 143, 92 S.Ct. 1921, 32 L.Ed.2d 612 (1972), upon which the prosecution relies in urging reversal. In Adams, a person known to a police officer approached the officer and informed him that an individual seated in a nearby vehicle was carrying narcotics and had a gun at his waist. The officer approached the vehicle and tapped on the window. When the occupant rolled down the window, the officer reached in and removed the revolver from the occupant’s waistband. In holding that the tip justified the officer’s initial actions, the Court emphasized that the officer knew the informant, the informant had provided reliable information in the past, and he might have been subject to immediate arrest for making a false complaint. The Court stated:
Some tips, completely lacking in indicia of reliability, would either warrant no police response or require further investigation before a forcible stop of a suspect would be authorized. But in some situations — for example, when the victim of a street crime seeks immediate police aid and gives a description of his assailant, or when a credible informant warns of a specific impending crime— ... an appropriate police response [is warranted].
407 U.S. at 147, 92 S.Ct. at 1924.
The prosecution argues that the specificity of the caller’s information provided sufficient indicia of reliability to create reasonable suspicion in this case. The caller’s information, however, was not very specific *193or complete. The caller did not provide the exact address on Chipeta, a description of the defendant, or the defendant’s destination. The caller did not indicate when the cocaine had been hidden in the car or how the caller knew that it was there. Furthermore, the caller did not mention that the defendant would be accompanied by a woman.5
Although the caller’s description of the car parked in an alley along the 300 block of Chipeta and the caller’s prediction that a person would enter the car at approximately 1:00 p.m. were corroborated by police surveillance,6 these facts are not at all suspicious. In this respect, this case differs from People v. Contreras, 780 P.2d 552 (Colo.1989), in which the anonymous informant’s report that a “car strip” was in progress at a specified location was corroborated by police observation of the stripped car. In Contreras, we held that the combination of the tip and the corroboration supported the on-scene stop of a person who stepped out of a vehicle matching the informant’s description of the vehicle into which the car parts had been loaded. In the present case, however, the information corroborated prior to the stop was commonplace and unremarkable. It was not sufficient in character or extent to suggest reliably that the informant had particularized knowledge of the defendant’s activities. Compare this case with People v. Villiard (police surveillance corroborated description of defendant and pattern of activity consistent with tip that defendant was engaged in drug transaction).
The constitutional permissibility of each stop must be determined on its own facts based upon the totality of the circumstances. This requires line-drawing in a manner sensitive at once to the defendant’s constitutional rights to be free from unreasonable seizure and to the importance of allowing law enforcement officers scope for prompt investigation of criminal activity. In this case the informant was anonymous. The informant did not indicate how or when he or she acquired the information supplied to Crime Stoppers. The only information corroborated prior to the stop was that a man would leave a described group of apartments at a particular time and would enter a described car and drive away — a pattern of conduct intrinsically unsuspi-cious. In sum, the credibility of the informant and the basis of the informant’s knowledge were unknown. Only the corroboration of one instance of commonplace activity suggested that the tip was reliable. We hold no more than that considering the facts of this case in totality, the police officers lacked an articulable and specific basis in fact for suspecting that criminal activity was afoot. The investigatory stop, therefore, failed to satisfy the requirements of Terry and Stone and was a constitutionally impermissible intrusion into the defendant’s personal security.
III.
Because the officers lacked reasonable suspicion to justify stopping the defendant, the trial court properly suppressed evi*194dence found in the search of the vehicle as fruit of the poisonous tree. See Alderman v. United States, 394 U.S. 165, 176-77, 89 S.Ct. 961, 968-69, 22 L.Ed.2d 176 (1969); Wong Sun v. United States, 371 U.S. 471, 484-86, 83 S.Ct. 407, 415-17, 9 L.Ed.2d 441 (1963); People v. Briggs, 709 P.2d 911, 915 (Colo.1985); People v. Madson, 638 P.2d 18, 33 (Colo.1981).
IV.
Accordingly, we affirm the trial court’s order suppressing evidence found in the search of the vehicle the defendant was driving. The case is remanded for further proceedings consistent with this opinion.
ROVIRA, J., dissents and QUINN, C.J. and MULLARKEY, J., join in the dissent.. Crime Stoppers is a program designed to encourage members of the public to report information about crime. Callers remain anonymous.
. The trial court found this consent to have been given voluntarily, and that ruling is not at issue in this appeal.
. The fourth amendment to the United States Constitution provides, in pertinent part, that "[t]he right of the people to be secure in their persons ... against unreasonable searches and seizures shall not be violated.”
. Article II, § 7, of the Colorado Constitution provides, in pertinent part, that "[t]he people shall be secure in their persons ... from unreasonable searches and seizures.”
. In Illinois v. Gates, 462 U.S. 213, 103 S.Ct. 2317, 76 L.Ed.2d 527 (1983), the United States Supreme Court adopted a totality-of-the-circumstances analysis to determine whether information supplied by an informant establishes probable cause to support the issuance of a search warrant. In doing so, it rejected the more rigid two-pronged test of Spinelli v. United States, 393 U.S. 410, 89 S.Ct. 584, 21 L.Ed.2d 637 (1969), that had required a showing that the informant was credible or the information was reliable and that the informant had an adequate basis for the information supplied. In doing so, however, the Court held that the Spinelli requirements remain relevant considerations in determining probable cause. We adopted the totality of the circumstances analysis in People v. Pannebaker, 714 P.2d 904 (Colo.1986).
Although the requirement of probable cause is more stringent than that of reasonable suspicion, the treatment of anonymous tips in the probable cause context is instructive. In this case, the informant's tip failed to establish the credibility of the informant, the reliability of the information or the basis of the informant’s knowledge that there was cocaine under the hood of the defendant's vehicle.
. In its brief, the prosecution argues that the caller’s identification of the defendant was also corroborated. That corroboration, however, was not obtained until after the officers stopped the defendant and, therefore, is irrelevant to the reasonable suspicion determination.