This is a continuation ofDetective Dennis Kilcoyne's, LAPD Robbery-Homicide Division, talk given at the California Crime Writer's Conference in June 2011. Part 1 is here.
Kilcoyne had more to say about investigating the "Black Widows": Helen Golay and Olga Rutterschmidt.
When the day came to apprehend the girls, Rutterschmidt's arrest went smoothly. Kilcoyne was concerned about taking down "the mastermind" Golay and planned for every eventuality. Kilcoyne had a video crew on-scene because he wanted a record if Golay accused the cops of wrongdoing.
I did some research and the book was likely The Sociopath Next Door by Martha Stout. Truly, you can't make this stuff up.
After they pulled Golay, then 74, out of the house and she was standing on the sidewalk in her see-through nightie, handcuffed, Kilcoyne had a chance to razz the FBI agent whose eyes dropped when looking at Golay. "Caught you looking, Opie. Got it on tape."