OPINION BY FITZGERALD, J.:

Appellant, Daniel Patrick Cauley, appeals from the judgment of sentence entered in the Westmoreland County Court of Common Pleas, following his conviction for driving under the influence, highest rate of alcohol.1 Appellant contends on appeal that the police did not have reasonable suspicion to conduct field sobriety tests. We hold that police officers may conduct sobriety tests after a citizen effectuates an encounter when the officer observes evidence of alcohol intoxication as a result of the encounter, and the officer observed the citizen driving a vehicle immediately prior to the encounter. Accordingly, we affirm.

The trial court adequately stated the facts:

Trial Ct. Op. at 1-3.

On appeal, Appellant argues that Officer Bell did not have reasonable suspicion to believe Appellant had engaged or was engaging in criminal activity. Appellant asserts that Officer Bell did not witness any motor vehicle violations and that he observed nothing remarkable about the way Appellant operated his vehicle. Appellant contends that, in the absence of any discernible facts to support a suspicion that he was driving under the influence, Officer Bell did not have the requisite reasonable suspicion to conduct the sobriety tests. We disagree.

Our standard of review for suppression rulings is well-established:

Commonwealth v. Bomar, 573 Pa. 426, 445, 826 A.2d 831, 842 (2003).

The legal standard of proof required by a police officer when engaging or interacting with a citizen varies depending on whether the citizen has been detained, and if so, the degree of the detention and the circumstances surrounding the interaction. See Commonwealth v. Sands, 887 A.2d 261, 268-69 (Pa.Super.2005) (quoting Commonwealth v. Hill, 874 A.2d 1214, 1217 (Pa.Super.2005)). There are three basic levels of interaction between citizens and police officers, and the accompanying standard of proof needed for each level is firmly established:

Id. (quoting Hill, 874 A.2d at 1217); see also Terry v. Ohio, 392 U.S. 1, 23-26, 88 S.Ct. 1868, 20 L.Ed.2d 889 (1968). "`No constitutional provision prohibits police officers from approaching a citizen in public to make inquiries of them.' However, `if the police action becomes too intrusive, a mere encounter may escalate into an investigatory [detention] or seizure.'" Commonwealth v. Beasley, 761 A.2d 621, 624 (Pa.Super.2000) (quoting Commonwealth v. Boswell, 554 Pa. 275, 283-84, 721 A.2d 336, 339-40 (1998) (plurality)). "The term `mere encounter' refers to certain non-coercive interactions with the police that do not rise to the level of a seizure of the person under the fourth amendment." Commonwealth v. Peters, 434 Pa.Super. 268, 642 A.2d 1126, 1129 (1994) (quoting Commonwealth v. Bennett, 412 Pa.Super. 603, 604 A.2d 276, 280 (1992)). For example, a mere encounter transpires when an officer approaches a citizen on a public street for the purpose of making inquiries. Id. (quoting Bennett, 604 A.2d at 280).

In contrast, "[a]n investigative detention occurs when a police officer temporarily detains an individual by means of physical force or a show of authority for investigative purposes." Commonwealth v. Smith, 904 A.2d 30, 35 (Pa.Super.2006) (quoting Commonwealth v. Barber, 889 A.2d 587, 592 (Pa.Super.2005)). In other words, in view of all the circumstances, if a reasonable person would have believed that he was not free to leave, then the interaction constitutes an investigatory detention. See Peters, 642 A.2d at 1129 (quoting Commonwealth v. Harper, 416 Pa.Super. 608, 611 A.2d 1211, 1215 (1992)); Hill, 874 A.2d at 1218-19 (quoting Commonwealth v. Johonoson, 844 A.2d 556, 562 (Pa.Super.2004)). An investigatory detention triggers the constitutional protection of the Fourth Amendment to the United States Constitution, Article I, Section 8 of the Pennsylvania Constitution, and the prerequisites for such a detention as set forth in Terry, supra.3 Smith, 904 A.2d at 35 (quoting Barber, 889 A.2d. at 592).

An investigative detention is lawful if supported by reasonable suspicion. Sands, 887 A.2d at 269 (quoting Hill, 874 A.2d at 1217). "To meet the standard of reasonable suspicion, the officer must point to specific and articulable facts which, together with the rational inferences therefrom, reasonably warrant the intrusion." Smith, 904 A.2d at 35 (quotation omitted). In addition, "we must look to the totality of the circumstances to determine whether the officer had reasonable suspicion that criminal activity was afoot." Id. at 35-36 (quoting Barber, 889 A.2d at 593). An investigative detention may last "as is necessary to confirm or dispel such suspicion." Commonwealth v. LaMonte, 859 A.2d 495, 500 (Pa.Super.2004) (quoting Commonwealth v. Strickler, 563 Pa. 47, 58, 757 A.2d 884, 889 (2000)). Because the level of intrusion may change during the course of the encounter, the record must be carefully scrutinized for any evidence of such changes. Commonwealth v. Blair, 860 A.2d 567, 572 (Pa.Super.2004) (citing Strickler, 563 Pa. at 58-60, 72-73, 757 A.2d at 889-91, 897-98).

Upon review and in consideration of the circumstances of this case, we find that the trial court did not err in concluding Officer Bell had reasonable suspicion to detain Appellant and submit him to field sobriety tests. The initial contact between Appellant and Officer Bell was not initiated by Officer Bell; rather, upon parking his vehicle, Appellant immediately approached the officer and began asking him why he was at that particular location. N.T. Suppression Hearing, 7/13/09, at 6, 9. A police officer need not possess reasonable suspicion in order to approach a citizen and ask him a question or request information from him. See Beasley, supra; Sands, supra. Certainly, an officer then does not require reasonable suspicion when a citizen voluntarily approaches the officer and speaks to the officer on his own accord. Officer Bell did not detain Appellant when he exited his vehicle nor did he initiate the conversation. N.T. Suppression Hearing, at 6, 9. There is also no reason to require Officer Bell, and other officers similarly situated, to take any special constitutional precautions with citizens who voluntarily approach them to make certain inquiries, as Appellant did in this case. Although it may not have been unreasonable for Appellant to inquire as to the purpose of Officer Bell's presence at his girlfriend's residence, neither was Appellant compelled to speak with Officer Bell, and he could have left the area or ignored him. See Peters, supra; Hill, supra. The initial interaction between Appellant and Officer Bell was therefore, at the most, a mere encounter, and the fact that Appellant initiated a conversation with him does not give rise to a constitutional requirement on behalf of Officer Bell to possess reasonable suspicion before speaking with Appellant. See Sands, supra; Beasley, supra.

Prior to the sobriety tests, when Appellant approached Officer Bell and asked him why he was at the residence, Officer Bell noticed indicia of intoxication, as he smelled a strong odor of alcohol on Appellant's breath and observed that Appellant's eyes were bloodshot. N.T. Suppression Hearing, at 6, 9. Based on his observations, Officer Bell asked Appellant to perform field sobriety tests. Id. at 7. Officer Bell admitted that when he asked Appellant to submit to a field sobriety test, Appellant was not free to leave. Id. At this point, the interaction between Appellant and Officer Bell was no longer a mere encounter, but transformed into an investigative detention, upon which reasonable suspicion was required. See Barber, supra; Sands, supra; Blair, supra.

We have no hesitation in concluding Officer Bell possessed the requisite reasonable suspicion. Upon speaking with Appellant, Officer Bell observed a strong odor of alcohol emanating from Appellant and Appellant's bloodshot eyes, both classic signs of intoxication. N.T. Suppression Hearing at 6-7, 9; see Commonwealth v. Angel, 946 A.2d 115, 118 (Pa.Super.2008) (stating that classic signs of intoxication include odor of alcohol, slurred speech, and glassy eyes). Officer Bell not only had indicia of Appellant's intoxication, but he also observed Appellant operating a motor vehicle immediately prior to their interaction. Officer Bell pointed to articulable and specific facts that gave rise to the probability that Appellant was driving under the influence. To the extent Appellant argues Officer Bell did not see him commit a violation of the Motor Vehicle Code, such evidence is necessary to support a traffic stop, not mere encounters. See 75 Pa.C.S. § 6308(b); Angel, 946 A.2d at 117-18. Officer Bell was permitted to draw the inference that Appellant, having driven to the scene and immediately exhibited signs of intoxication, drove to the scene while intoxicated. Accordingly, Officer Bell lawfully submitted Appellant to field sobriety tests to confirm or dispel his suspicions. See Smith, supra; LaMonte, supra.

Finally, as a result of the sobriety test, Officer Bell had probable cause to arrest Appellant. Appellant offers no substantial argument to the contrary. Accordingly, we hold that the trial court properly denied Appellant's motion to suppress after receiving evidence that Officer Bell saw Appellant drive a motor vehicle, immediately approach the officer, and immediately exhibit signs of intoxication.

Judgment of sentence affirmed.