This was Jessie Royce Landis' final acting role before her death on February 2, 1972 at the age of 75.
The new car that is delivered to Beth Chadwick is a Ferrari 365GTB.
The drive-in hamburger stand where Columbo takes Peter Hamilton (Leslie Nielsen) to lunch is the same one where Vicki Lester (Judy Garland) works as a carhop in "A Star is Born," and also where Spencer Tracy and Katherine Hepburn go for ice cream and coffee in "Guess Who's Coming to Dinner?".
The woman who speaks to Columbo in the courtroom is Marcia Wallace, best known for her role as Carol Kester in "The Bob Newhart Show" (1972-1978).