This was meant to be part of a rotating series of detectives shows with Sherlock Holmes (Stewart Granger), Nick Carter (Robert Conrad) and Charlie Chan (Ross Martin) but the corresponding TV movies never got good enough ratings so it never materialized.
Malloy/Bob Hastings played Lt (Senior Grade) Elroy Carpenter on McHale's Navy. In WW2, Hastings was an USAAF Navigator on a B-29 in the Pacific.
This was an attempt to revive what had been a popular mystery franchise at RKO in the 1930s - The Hildegarde Withers movies, which generated multiple B-movie titles (including The Penguin Pool Murder and The Plot Thickens). The starring role, that of a school teacher and amateur sleuth who works alongside a policeman to solve murder cases, had been played first by Edna May Oliver and later by Helen Broderick and Zasu Pitts.
This was a rare example of network television trying to embrace San Francisco's "hippie culture" of the late 1960s and early 1970s in a mainstream movie. Our Miss Brooks alum Eve Arden as Hildegarde Withers is a prototypical "fish out of water" in this failed TV pilot..
Although this film's plot bears certain similarities to the real life case of kidnapped San Francisco heiress Patty Hearst, it was made two years before that incident occured.