They were doing that before the Glock, too. The Rolling Stones made a song about it back in the Stoned Age - Doo Doo Doo Doo Doo aka Heartbreaker.
http://www.youtube.com/watch?v=lpY0ovAJAsk
Remember, many New York City cops interpretation of the New York Reload was to fire both of their revolvers at once.
Dad was NYPD. he retired in ‘68. He joined up in 46 right after the Marines and WW II. Because of the Marines he knew how to shoot and taught me how to shoot. You cannot say that the bulk of NYPD knows how to shoot. It seems pray and spray is de rigueur with the department.