From Wikipedia:
The French Connection is a 1971 American neo-noir crime action thriller film starring Gene Hackman, Roy Scheider, and Fernando Rey, and directed by William Friedkin. The screenplay, written by Ernest Tidyman, is based on Robin Moore’s 1969 book of the same name. It tells the story of fictional NYPD detectives Jimmy “Popeye” Doyle and Buddy “Cloudy” Russo, whose real-life counterparts were Narcotics Detectives Eddie Egan and Sonny Grosso, in pursuit of wealthy French heroin smuggler Alain Charnier (played by Rey).
The title appears to use a phototype version of bold condensed Beton, with stretched letterforms. On a similar note, the yellow tagline looks like the bold weight of Kabel Condensed, but isn’t a perfect match when compared to the metal original (or to the adaptation by Lettergraphics, for that matter), see for example the ear of g. The oblique grotesque used for the blue text is unidentified. Credits are set in Helvetica Condensed.