Authorities say Daniel Cleary, 48, told the apartment manager he was an FBI agent after the manager noticed Cleary was wearing a gun when she went to investigate a water leak in the apartment, the South Florida Sun-Sentinel reported Wednesday.
The manager became suspicious and called sheriff's deputies, the newspaper said.
Prosecutors say Cleary identified himself to deputies as an FBI agent and was carrying a Glock handgun and counterfeit FBI credentials bearing his name and photograph.
In the apartment, deputies found two fake FBI badges and 28 other counterfeit federal badges from agencies including the U.S. Secret Service, U.S. Marshals Service, Drug Enforcement Administration and the Federal Aviation Administration, authorities said.
Cleary was arrested and booked at the Broward County jail and released after posting bond.
If convicted, Cleary could face as long as three years in prison on each count of impersonation and six months on each count of possession of federal agency badges and credentials.