During shooting, Bay and his actors would frequently get together on their Sundays off to work on the tempo of their dialogue and blocking. Bay videotaped the sessions and then transcribed any newly improvised lines into the script and distributed them to the cast the next day. The improvisations, he said, brought out comedy in non-comedic moments and helped unearth new quirks in the characters.
"In the first Bad Boys, I tried to take an old, tired buddy cop story and make it feel fresh through my visuals and cutting style, and by using the great chemistry between Martin and Will. But in the end, it was the chemistry that took the movie to new heights."
As Bruckheimer has learned from the countless hit motion pictures he’s produced, "when you put one gifted performer with another, both excel. And if you’re lucky and they happen to like and respect each other, as Will and Martin do, a great camaraderie develops. It was amazing to watch them in rehearsals. They would actually come up with ideas for each other. There was never a selfish moment between them."
In Bad Boys II, Bay was striving for a different tone than the original. "The first movie was more sensational," says Bay. "I tried to make this one a little edgier and more real. In the same way that I surrounded Sean Connery and Nicolas Cage in The Rock with real Navy S.E.A.L.s, I surrounded Will and Martin with real cops and it made a huge difference."
Most of the T.N.T. [Tactical Narcotics Team] squad portrayed in the film is comprised of actual members of the Miami-Dade Police Force. The officers, along with their undercover associates (who could not be filmed for obvious reasons), also assisted in training the actors. Harry Humphries, who Bruckheimer and Bay met while filming The Rock, acted as a supervising technical advisor on Bad BoysII, while Lt. William Erfurth, a former commanding officer of Miami-Dade’s T.N.T. unit, was invaluable both to the screenwriters and the performers, assisting in every facet of production. Erfurth not only contributed his expertise in terms of dialogue and procedural responses, he coordinated the schedules of his best T.N.T. personnel, so that the filmmakers could utilize the real-life officers in roles as part of Marcus and Mike’s highly trained unit.
"Bill Erfurth has a sterling reputation within the Miami-Dade police force and beyond," says Bruckheimer. "In doing our research, we found that arrests during his tenure with T.N.T. skyrocketed, as did convictions. He and Harry Humphries made sure that we kept as close to reality as possible when it came to using the S.W.A.T. and T.N.T. teams. If we tried to veer too far off course, they’d rein us back in. So anytime you see someone in uniform in this movie, chances are they’re an officer in one of the city or county police departments."
During pre-production, art and life converged. Donning bulletproof vests, Bruckheimer and Bay spent the evening on patrol with Lt. Erfurth. While on a police department’s "Ride Along" program, Bay actually assisted in the arrest of a wanted felon by pointing out a seemingly innocuous passerby who fit the description of a man the police were attempting to locate. They now refer to him as 'Captain Bay.'