18 USC 3141 - Release and detention authority generally

(a) Pending Trial.— 
A judicial officer authorized to order the arrest of a person under section 3041 of this title before whom an arrested person is brought shall order that such person be released or detained, pending judicial proceedings, under this chapter.
(b) Pending Sentence or Appeal.— 
A judicial officer of a court of original jurisdiction over an offense, or a judicial officer of a Federal appellate court, shall order that, pending imposition or execution of sentence, or pending appeal of conviction or sentence, a person be released or detained under this chapter.