There were 2 Secretaries, the first was Cynthia Lynn, who played "Helga", Bob Crane had a long time affair with her.
She was replaced by Patricia Olson (stage name Sigrid Valdis) who played "Hilda", her and Bob Crane were married for 9 years.
Crane actually made amateur pornos with unknowing co stars together with his friend John Carpenter, who many believe actually killed him, bludgeoned him to death with a camera tripod. He used to show them around the movie sets together with the stills of his many conquests, how to kill a career.
Always a Bulldog