From Tactical Life:

About five years into my career, my agency made a significant change to its policy on authorized duty weapons. The change, which was rumored to have been prompted by aging and problematic duty weapons—specifically a light primer strike/failure to fire during an officer-involved shooting—allowed officers to purchase GLOCK firearms at their own expense. My agency not only allowed the officers to purchase GLOCK firearms, but it also allowed officers to choose from the G23, G22 or G35. In addition, detectives, administration personnel and off-duty officers could carry the subcompact G27.