De Seção de trivia do IMDB para o filme é o comentário do DVD:
The scene where Doyle and Russo chase down the dealer near the beginning and Gene Hackman shouts out his famous question "Did you ever pick your feet in Poughkeepsie?" is based on actual "good cop/bad cop" interrogations by the real "French Connection" detectives, Eddie Egan and Sonny Grosso according to William Friedkin in the DVD commentary. Grosso would gingerly ask a suspect direct questions about his crimes, then Egan would always butt in and yell unusual questions like the Poughkeepsie one. The suspect would get so rattled by Egan's offbeat questioning that he felt more comfortable answering Grosso's, thus, tending to eventually incriminate himself.
Se tomado pelo valor de face, isso significa que a linha não deve fazer sentido, na vida real ou no filme.