Thirty-eight-year-old Michael Miller of Chicago is also charged with threatening a public official.
The Cook County Sheriff's office says on two occasions in March Miller posed as a police officer to gain access to a judge and an assistant state's attorney, both in the Cook County Criminal Courts Building at 26th and California.
No one was harmed in either incident.
Miller had recently been paroled for a 12-year sentence for armed robbery after being convicted of shaking down drug dealers while working as a Ford Heights police officer.
