William Woolridge, 33, and Johnny Johnson, 21, are both charged with felony false impersonation of an officer.
Johnson also faces several other charges, including unlawful use of a weapon. Authorities say he flagged down police to ask a question while wearing body armor and a vest with the word "police" on it.
Johnson was taken into custody when he failed to produce any identification proving that he was an officer.
Authorities say Woolridge was arrested after identifying himself as a U.S. Army reservist military police officer at the Austin District station.