Atlanta PD used S&W pistols for a long time(since 1940s), but now they have switched to Glock. Patrolmen will get Glock 22 Gen4 and SWAT will get Glock 21 Gen4. There are plenty of discussions going on including the choice was for local economy, S&W dropped the ball on this one, to Glock really under-bidding.
From: The Tactical Wire