Is it possible that this story could actually be a combination of more than one incident? I have researched this murder as described and located two stories.
The first fits the name but not the incident. Lt. Beaufort Swancutt murdered his Long Beach, CA girlfriend and several others on March 5, 1944. (Search for "Swancutt, murder" to read newspaper articles about the incident. This is one example: http://news.google.com/newspapers?nid=1368&dat=19440708&...
The other is a California murder involving a man by a different name, but otherwise fitting the description. Raymond “Rattlesnake James” Lisenba, also known as Robert S. James, stuck his pregnant wife's foot in a box containing two rattlesnakes. She didn't die from the bites, so he drowned her in the bathtub. This incident happened in 1935, but the murderer was executed in 1942. Here are two sites describing the murder: http://en.wikipedia.org/wiki/Rattlesnake_Jameshttp://murderrevisited.blogspot.com/
I realize this doesn't cover the description of the murderer being a chiropractor, but it is I all could find.