The morning after the first murder, Steiger checks the newspapers for coverage. The back page of the New York Daily News reveals that the Philadelphia Phillies edged the New York Mets 6 to 5 and that the Kansas City Athletics shut out the New York Yankees 2 to 0. The edition of the paper Steiger is reading is therefore from Thursday, June 29, 1967 (reporting on games played on the evening of June 28, the previous day).
Rod Steiger was initially approached to play the put-upon Jewish cop, not the fiendish serial killer - perhaps because he had recently had a great success playing a Jewish character in "The Pawnbroker", and because the cop was the hero. After he told the producer that whoever played the killer would steal the film, he was offered that part instead. It is worth noting that the part of the killer has been greatly expanded in the film from William Goldman's novel, where the cop is definitely the central character.
One of Rod Steiger's impersonations is of comedian W.C. Fields. Steiger would portray Fields eight years later, in W.C. Fields et moi (1976).
The film was playing in Vallejo, California in April 1969, just after the Zodiac Killer murdered his first known victims, also in Vallejo. Many criminologists believe that the Zodiac Killer was a movie buff or was influenced by motion pictures, and that he took ideas and phrases from movies for his taunting missives to the police and to area newspapers, which began in August 1969. Others believe that he was from Vallejo. The fact that "No Way To Treat a Lady" was about a serial killer who enjoys taunting the policeman on his trail makes it an interesting footnote to the Zodiac Killer case.
One of the actors named on the Othello poster outside the Amanda Gill Playhouse is William Pratt. William Henry Pratt is the real name of Boris Karloff.