When Paris is calling Barney to say that someone had taken Dana, a George Dickel Souvenir whiskey bottle can be seen. This type of bottle was also used as "Saurian brandy" on Star Trek.
Leonard Nimoy as Spock was also in the similarly named Star Trek episode 'Cat's Paw'.
The set of Millie's apartment is the same one used for Alma's (played by Cicely Tyson) in Death Squad (1970).
Greg Morris's character (Barney) went undercover as a gangster, befriending a woman whom he had to set up in order to get the criminal in charge. 15 years later, his son Phil Morris did the same thing in The Young and the Restless.