According to the Chicago Police Department's Web site, Penelope Trahanas is the district's commander.
An order of protection was issued against Trahanas last week after she allegedly made threatening phone calls to a former boyfriend, who is another police officer. He is identified as Matthew Jackson.
On Tuesday night, Trahanas turned herself in and was charged with telephone harassment.
Jackson alleges Trahanas left a voice mail suggesting she could ruin his career. The pair dated for two years.
Trahanas denies she committed a crime against Jackson.
Police say Trahanas has been relieved of police powers pending further internal review and completion of the IPRA investigation.