Actually, that applies to first-time illegals too, 8 USC 1325, referencing the criminal code, 18 USC, for penalties.
(a) Any alien who (1) enters or attempts to enter the United States at any time or place other than as designated by immigration officers, or (2) eludes examination or inspection by immigration officers, or (3) attempts to enter or obtains entry to the United States by a willfully false or misleading representation or the willful concealment of a material fact, shall, for the first commission of any such offense, be fined under title 18, United States Code, or imprisoned not more than 6 months, or both, and, for a subsequent commission of any such offense, be fined under title 18, United States Code, or imprisoned not more than 2 years, or both.
(a) Any alien who (1) enters or attempts to enter the United States at any time or place other than as designated by immigration officers, or (2) eludes examination or inspection by immigration officers, or (3) attempts to enter or obtains entry to the United States by a willfully false or misleading representation or the willful concealment of a material fact, shall, for the first commission of any such offense, be fined under title 18, United States Code, or imprisoned not more than 6 months, or both, and, for a subsequent commission of any such offense, be fined under title 18, United States Code, or imprisoned not more than 2 years, or both.