N.C. Gen. Stat. § 1-435: Bail may arrest defendant.

For the purpose of surrendering the defendant, the bail, at any time or place, before they are finally charged, may themselves arrest him, or by a written authority endorsed on a certified copy of the undertaking may empower any person over 21 years of age to do so. (C.C.P., s. 159; Code, s. 301; Rev., s. 753; C.S., s. 793.)