Wrong. Reread the Policy: all uniformed officers are required to wear body armor while working on or off duty. The officers then have the additional OPTION of wearing it externally, IF it meets their policy standards.
"POLICY: To maximize officer safety through the use of body armor in combination with prescribed safety procedures.
The wearing of body armor is mandatory for all sworn employees while wearing the uniform when working on or off duty, who are involved in any enforcement activities.
Sworn employees electing to wear a body armor external vest carrier shall adhere to the standards and specifications outlined in section 3-121.08 of the MPD policy manual."