Richard Crenna
So, the first version of "Double Indemnity" was a real "film noir" film, made in 1944. Then, there was a version done in 1973, that was almost word for word like the B&W. Richard Crenna played Walter Neff in that. {Maybe some of you have been finding it being shown on HBO lately}. So, it was only fair and rather a great choice in "Body Heat", made in 1981, that Richard Crenna played the husband they murder. Kasdan also made his role a real role too. He wasn't just talked about and then a dead body.
Also, they changed the names, but kept them somewhat similar. In "DB" it was Walter Neff. And then Hurt played Ned (get it), and Matty and Edmund were the Walkers (close to Walter as a name).
So, Kasdan did pay homage to James M. Cain who wrote the novel and Raymond Chandler and Billy Wilder who wrote the '44 screenplay, and Wilder who directed that one.
Just interesting, I thought.