"M"

The door is opening as a man is dragging a squealing kid out of the auditorium of an unidentified theatre in Joseph Losey's "M" (Columbia, 1951). The film stars David Wayne, Howard Da Silva and Martin Gabel.

A killer of children is on the loose and other patrons think this is the guy so they beat him up a little. Note the posters in the cases for "The Red Shoes." Recognize that terrazzo pattern?

They apologize after learning that the girl is the man's daughter. 

Later we spend a bit of time on the Promenade at Ocean Park where the killer likes buying candy and balloons for kids he meets. Here we get the signage for the Dome Theatre in the background. See the page about the Dome Theatre on the Los Angeles Theatres site for a history of the theatre as well as many photos.

The blind balloon seller has put a chalk "M" on the guy's back after he recognizes a tune the killer plays on the flute. He alerts another worker, who gives chase. The marquee we see here isn't the Dome but a space that at various times was the Casino Gardens Ballroom and the Fun Palace.

We get a look at a number of other L.A. locations including many shots on Bunker Hill, in the 3rd St. Tunnel, and a fine sequence inside the Bradbury Building.

On IMDb: "M"