Edited sentence: (A) enforce Federal laws and regulations for the protection of persons and property;.(B) carry firearms;.(C) make arrests without a warrant for any offense against the United States committed in the presence of the officer or agent or for any felony cognizable under the laws of the United States if the officer or agent has reasonable grounds to believe that the person to be arrested has committed or is committing a felony;.(D) serve warrants and subpoenas issued under the authority of the United States;.(E) conduct investigations, on and off the property in question, of offenses that may have been committed against property owned or occupied by the Federal Government or persons on the property; and.(F) carry out such other activities for the promotion of homeland security as the Secretary may prescribe.- While engaged in the performance of official duties, an officer or agent designated under this subsection may -