Brenda Vaccaro in Dear Detective (1979)

This 1979 pilot film and subsequent series features Brenda Vaccaro as a single mother and police detective trying to hold it all together. She's dating a classics professor and trying to solve a series of murders. The production is based on a french film of the same name starring Anne Giradot.

There's very little video of the series available. The opening credits is featured in a compilation of show-opens from 1979.  It was uploaded to YouTube by bobtwcatlanta.

Obscurity factor: 10 (hard to find, not on DVD, largely forgotten)