Tenn. Code Ann. § 33-6-402: Detention without warrant authorized

If an officer authorized to make arrests in the state, a licensed physician, a psychologist authorized under § 33-6-427(a) , or a professional designated by the commissioner under § 33-6-427(b) has reason to believe that a person is subject to detention under § 33-6-401 , then the officer, physician, psychologist, or designated professional may take the person into custody without a civil order or warrant for immediate examination under § 33-6-404 for certification of need for care and treatment.