What is the legal definition of investigative detention ? A routine traffic stop closely resembles an investigative detention. Berkemer v. McCarty, 468 U.S. 420, 104 S. Ct. 3138, 82 L. Ed. 2d 317 (1984). An investigative detention is a seizure. Francis v. State, 922 S.W.2d 176, 178 (Tex. Crim. App. 1996), so it must be reasonable to meet the standards required by the United States and Texas Constitutions. See U.S. CONST. amend. IV; TEX. CONST. art. I, 9. To determine the reasonableness of an investigative detention under the Fourth Amendment, we apply the guidelines set out by the United States Supreme Court in Terry v. Ohio: (1) whether the officer's action was justified at its inception; (2) whether it was reasonably related in scope to the circumstances that initially justified the interference. See Davis v. State, 947 S.W.2d 240, 242 (Tex. Crim. App. 1997) (citing Terry v. Ohio, 392 U.S. 1, 19-20, 88 S. Ct. 1868, 20 L. Ed. 2d 889 (1968)). Under the first guideline, an officer's reasonable suspicion justifies an investigative detention. See Davis v. State, 947 S.W.2d at 242-43 (citing Terry v. Ohio, 392 U.S. at 27). Specifically, the officer must have a reasonable suspicion that some activity out of the ordinary is occurring or has occurred, some suggestion to connect the detainee with the unusual activity, and some indication the unusual activity is related to crime. See Davis v. State, 947 S.W.2d at 244 (citing Garza v. State, 771 S.W.2d 549, 558 (Tex. Crim. App. 1989)). To determine whether an officer was reasonable in his initial action, we ask whether, in light of the officer's experience and knowledge, there existed specific articulable facts which, taken together with rational inferences from those facts, reasonably warranted that intrusion. See Davis v. State, 947 S.W.2d at 242. We give due weight, not to the officer's inchoate and unparticularized suspicion or "hunch," but to the specific reasonable inferences he is entitled to draw from the facts in light of his experience. See Davis, 947 S.W.2d at 243 n.3. In addition, we determine reasonableness based on the totality of the circumstances. Woods v. State, 956 S.W.2d 33, 38 (Tex. Crim. App. 1997). We use an objective standard: would the facts available to the officer at the moment of the seizure warrant a person of reasonable caution in the belief that the action taken was appropriate. See Davis v. State, 947 S.W.2d at 243. An investigative detention that is not based on reasonable suspicion is unreasonable and thus violates the Fourth Amendment. Id. An officer may lawfully stop a motorist who commits a traffic violation. McVickers v. State, 874 S.W.2d 662, 664 (Tex. Crim. App. 1993); Armitage v. State, 637 S.W.2d 936, 939 (Tex. Crim. App. 1982). If an officer has a reasonable basis for suspecting that a person has committed a traffic offense, the officer may legally initiate a traffic stop. the officer also may detain a person who commits a traffic violation. Garcia v. State, 827 S.W.2d 937, 944 (Tex. Crim. App. 1992).