In the opening credits, the answering machine of director Lawrence Doheny calls Rockford's machine. Doheny's referred to as Larry Doheny.
The helicopter used in the final chase scene is a Bell 206B JetRanger II (reg n°. N20DB) and had been used in other films and TV shows. The helicopter was involved in a crash ten years later that killed 2 of 3 passengers.
A similar premise to this story had previously been used (twice) - once in James Garner's series, Maverick (1957); the in Shady Deal at Sunny Acres (1958), and Dreadful Sorry Clementine (1971). All 3 were written by Roy Huggins on shows he created/produced.
When sheriff Mitchell (Dana Elcar)'s taking Rockford's prints, he's not doing it correctly. When a person's prints are actually taken, each finger's rolled - by doing so, it ensures the entirety of the digit's been recorded. Instead, the sheriff just inks each one, then 'plops' Jim's finger straight down, and then he moves to the next finger