Nancy Perez said the officers were accused of ignoring emergency calls, filing false police reports and lying about calls they handled, The Miami Herald reported.
The discharged officers are all from the Kendall District squad.
They are identified as Sgt. Jennifer Gonzalez and officers Dario Socarras and Jose Huerta.
Gonzalez was caught shopping, loading purchases into her patrol car and visiting her parents while on duty, the report said.
Socarras ignored emergency calls, including robbery, while spending time with his girlfriend and having coffee with Huerta, officials allege.
Three other Kendall District officers officers, Jeffrey Price, Fabian Owens and Ivan Tomas, were suspended without pay in September and are now back at work, Perez said.
They were accused of ignoring a number of emergency calls.