In Franks v. State, 241 S.W.3d 135 (Tex. App.--Austin 2007, pet. ref'd), a police officer noticed a vehicle parked just off the highway "after dark." Id. at 139. The vehicle was stopped at a rest area, but its engine was running and its dome light was on. Id. The officer parked his patrol car behind the vehicle, activated his overhead lights, approached the vehicle, and began talking to Franks, the driver and sole occupant of the vehicle. Id. At some point during the conversation, Franks asked the officer if she could leave. Id. The officer told her that she could not. Id. Eventually, Franks was asked to step out of her vehicle, the vehicle was searched, and cocaine was found. Id. Franks filed a motion to suppress the evidence, which the trial court denied. Id. at 140. The Court held that, once the officer refused Franks's request to leave, the encounter became an investigative detention requiring reasonable suspicion of criminal activity. Id. at 142-43. Finding none, this Court reversed the trial court's denial of the motion to suppress. Id. at 145. However, the Courtrt also explained why the initial interaction between the officer and Franks was not a detention: "The initial interaction between the officer and appellant, after he approached the car, was an encounter. Although the officer parked his vehicle behind appellant's, nothing in the record suggests that the position of his vehicle blocked hers or prevented appellant from leaving the rest area by simply driving forward. Moreover, appellant does not allege that the patrol car's siren was activated, that she received any command over the patrol car's loudspeaker, or that the officer told her to turn off her car's engine when he approached." Id. at 142. In sum, the officer had observed the defendant's vehicle parked in the same location at a rest area at different times over several days and decided to investigate. The officer parked his patrol car behind the defendant's car and activated his overhead lights. Id. at 139. He approached the defendant's car-the engine was running-and told the driver why he had stopped to investigate. Id. The driver appeared nervous and asked if she could leave, but the officer told her that she could not leave. Id. The court held that the initial encounter with the driver was consensual and did not require any justification but that the consensual encounter escalated into a detention at the moment the officer informed her that she could not leave. Id. at 142.