For Their Kinsey-Type Survey They Came To This — Hush-Hush Town
From the back:
There was a depraved killer loose in the town, and Sam Carter wanted him caught; but Sam had done too much research, knew too many dark secrets the citizens had kept hidden. And then he was in a jail cell, and coming at him with a rubber hose was probably the nation’s most beautiful interrogator, to make sure the city remained a —
Hush-Hush Town
Good Grief. Ember Library, 1966 and $99 on the two sites I could find it and Amazon. Amazing.