As we recently reiterated, one is in custody if, under the totality of the circumstances, a reasonable person believes that his freedom of movement was restrained to the degree associated with a formal arrest. Roberts v. State, No. 07-15-00282-CR, 2017 Tex. App. LEXIS 6019, at *12 (Tex. App.—Amarillo June 28, 2017, no pet.) (mem. op., not designated for publication). Here, the circumstances revealing that appellant's confession was voluntary also provided the trial court rational basis to find that he was not in custody when uttering the inculpatory statements.