Guest star Vic Perrin's fourth (of five) appearances on Dragnet (1967). He also guest starred in 16 episodes of Dragnet (1951) and the movie Dragnet (1954).
According to the voice-over by Jack Webb, back then, a size 9 was for "a small woman". (Since at least the '80s, a size 8-10 is a Medium size. Small would be size 4-6.)
In keeping with the show's peculiarity of showing the color orange prominently, there is a few seconds close-up on a bright orange light-bulb, for no particular reason other than the aforementioned.
"The courts protect the criminals these days, not the innocent." The year was 1969 when the violinist neighbor spoke these words to Gannon. He further added that the one thing he knows is that they can arrest the killer, but the courts would release him. What foresight this turned out to be for 2021, when---a whole 52 years later---all courts indeed appear to cater to criminals in Los Angeles, under George Gascon's ultra far-left agenda.
While initially investigating the murder scene, Gannon & Friday don't touch anything, until Friday picks up the wallet owned by the deceased. Since he was not wearing gloves or handling the wallet in a way not to transfer his own prints to the wallet, he would have "contaminated" that article & would have had to report this to the fingerprint artist upon his arrival at the scene. This interaction was never shown.