(a) Under the authority of 18 U.S.C. 3061,criminal;

(2) Make arrests without warrant for offenses against the United States committed in their presence;

(3) Make arrests without warrant for felonies cognizable under the laws of the United States if they have reasonable grounds to believe that the person to be arrested has committed or is committing such a felony;

(4) Carry firearms; and

(5) Make seizures of property as provided by law.

(b) Administrative subpoenas may be served by delivering a copy to a person or by mailing a copy to the person's last known address. For the purposes of this provision, delivery of a copy includes handing it to the party or leaving it at the party's office or residence with a person of suitable age and discretion employed or residing therein. Service by mail is complete upon mailing.