§1357. Powers of immigration officers and employees
(a) Powers without warrant
Any officer or employee of the Service authorized under regulations prescribed by the Attorney General shall have power without warrant-
(1) to interrogate any alien or person believed to be an alien as to his right to be or to remain in the United States;
(2) to arrest any alien who in his presence or view is entering or attempting to enter the United States in violation of any law or regulation made in pursuance of law regulating the admission, exclusion, expulsion, or removal of aliens, or to arrest any alien in the United States, if he has reason to believe that the alien so arrested is in the United States in violation of any such law or regulation and is likely to escape before a warrant can be obtained for his arrest, but the alien arrested shall be taken without unnecessary delay for examination before an officer of the Service having authority to examine aliens as to their right to enter or remain in the United States;
(3) within a reasonable distance from any external boundary of the United States, to board and search for aliens any vessel within the territorial waters of the United States and any railway car, aircraft, conveyance, or vehicle, and within a distance of twenty-five miles from any such external boundary to have access to private lands, but not dwellings, for the purpose of patrolling the border to prevent the illegal entry of aliens into the United States;
(4) to make arrests for felonies which have been committed and which are cognizable under any law of the United States regulating the admission, exclusion, expulsion, or removal of aliens, if he has reason to believe that the person so arrested is guilty of such felony and if there is likelihood of the person escaping before a warrant can be obtained for his arrest, but the person arrested shall be taken without unnecessary delay before the nearest available officer empowered to commit persons charged with offenses against the laws of the United States; and
(5) to make arrests-
(A) for any offense against the United States, if the offense is committed in the officer's or employee's presence, or
(B) for any felony cognizable under the laws of the United States, if the officer or employee has reasonable grounds to believe that the person to be arrested has committed or is committing such a felony,