Having the two protagonists mortally wound each other was one of the key factors in gaining Hays Office approval for the script: the Production Code demanded that criminals pay, on screen, for their transgressions.
In addition, Double Indemnity broke new cinematic ground on several fronts, one of these being the first time a Hollywood film explicitly explored the means, motives, and opportunity of committing a murder.
It took skillful performers to bring nuance to these treacherous characters, and casting the roles of Walter Neff and Phyllis Dietrichson was a challenge for Wilder.

Sistrom's and Wilder's first choice for the role of Phyllis Dietrichson was Barbara Stanwyck.
At the time, Stanwyck was the highest-paid actress in Hollywood as well as the highest-paid woman in America. (
Her eventual co-star MacMurray matched Stanwyck's prominence at the pay window: in 1943, he was the highest-paid actor in Hollywood, and the fourth highest-paid American.)
Given the nature of the role, Stanwyck was reluctant to take the part, fearing it would have an adverse effect on her career.
According to Stanwyck,
I said "I love the script and I love you, but I am a little afraid after all these years of playing heroines to go into an out-and-out killer."
And Mr. Wilder – and rightly so – looked at me and he said "Well, are you a mouse or an actress?"
And I said "Well, I hope I'm an actress."
He said "Then do the part".
And I did and I'm very grateful to him.

The character of Walter Neff was not only a heel, he was a weak and malleable heel – many Hollywood actors including Alan Ladd, James Cagney, Spencer Tracy, Gregory Peck, and Fredric March passed on it.
Wilder recalls "scraping the bottom of the barrel" and approaching George Raft.
Raft was illiterate, so Wilder had to tell him the plot.
About halfway through, Raft interrupted him with "Let's get to the lapel bit." "
What lapel bit?"
a bewildered Wilder replied. "
The lapel," the actor said, annoyed by such stupidity. "
You know, when the guy flashes his lapel, you see his badge, you know he's a detective."
This was his vision of the film, and because it wasn't part of the story, Raft turned the part down. (
This was the last in a series of roles turned down by Raft in films which turned out to be classics.)

Wilder finally realized that the part should be played by someone who could not only be a cynic, but a nice guy as well.

Fred MacMurray was accustomed to playing "happy-go-lucky good guys" in light comedies, and when Wilder first approached him about the Neff role, MacMurray said "You're making the mistake of your life!"
Playing a serious role required acting, he said "and I can't do it."
But Wilder pestered him about it every single day – at home, in the studio commissary, in his dressing room, on the sidewalk – until he simply wore the actor down.
MacMurray felt safe about his acquiescence because Paramount, which had him under contract and had carefully crafted his good guy image, would never let him play a "wrong" role.
His trust, however, was misplaced: His contract was up for renewal at the time, and because his friend and co-star Carole Lombard had shrewdly and successfully taught him how to play hardball with the studio bosses, he wasn't the pliable pushover of old.
Paramount executives decided to let him play the unsavory role to teach him a lesson.
A lesson was indeed taught, but not the one Paramount had in mind.
MacMurray made a great heel and his performance demonstrated new breadths of his acting talent. "
I never dreamed it would be the best picture I ever made," he said.

Edward G. Robinson was also reluctant to sign on for the role of Barton Keyes, but not for the same reasons as MacMurray and Stanwyck.
Having been a star since Little Caesar in 1930, this role represented a step downward to the third lead.
Robinson later admitted "At my age, it was time to begin thinking of character roles, to slide into middle and old age with the same grace as that marvelous actor Lewis Stone".
It also helped, as he freely admitted, that he drew the same salary as the two leads for f
Having the two protagonists mortally wound each other was one of the key factors in gaining Hays Office approval for the script: the Production Code demanded that criminals pay, on screen, for their transgressions. In addition, Double Indemnity broke new cinematic ground on several fronts, one of these being the first time a Hollywood film explicitly explored the means, motives, and opportunity of committing a murder. It took skillful performers to bring nuance to these treacherous characters, and casting the roles of Walter Neff and Phyllis Dietrichson was a challenge for Wilder.
Sistrom's and Wilder's first choice for the role of Phyllis Dietrichson was Barbara Stanwyck. At the time, Stanwyck was the highest-paid actress in Hollywood as well as the highest-paid woman in America. (Her eventual co-star MacMurray matched Stanwyck's prominence at the pay window: in 1943, he was the highest-paid actor in Hollywood, and the fourth highest-paid American.) Given the nature of the role, Stanwyck was reluctant to take the part, fearing it would have an adverse effect on her career. According to Stanwyck,
I said "I love the script and I love you, but I am a little afraid after all these years of playing heroines to go into an out-and-out killer." And Mr. Wilder – and rightly so – looked at me and he said "Well, are you a mouse or an actress?" And I said "Well, I hope I'm an actress." He said "Then do the part". And I did and I'm very grateful to him.
The character of Walter Neff was not only a heel, he was a weak and malleable heel – many Hollywood actors including Alan Ladd, James Cagney, Spencer Tracy, Gregory Peck, and Fredric March passed on it. Wilder recalls "scraping the bottom of the barrel" and approaching George Raft. Raft was illiterate, so Wilder had to tell him the plot. About halfway through, Raft interrupted him with "Let's get to the lapel bit." "What lapel bit?" a bewildered Wilder replied. "The lapel," the actor said, annoyed by such stupidity. "You know, when the guy flashes his lapel, you see his badge, you know he's a detective." This was his vision of the film, and because it wasn't part of the story, Raft turned the part down. (This was the last in a series of roles turned down by Raft in films which turned out to be classics.)
Wilder finally realized that the part should be played by someone who could not only be a cynic, but a nice guy as well.
Fred MacMurray was accustomed to playing "happy-go-lucky good guys" in light comedies, and when Wilder first approached him about the Neff role, MacMurray said "You're making the mistake of your life!" Playing a serious role required acting, he said "and I can't do it." But Wilder pestered him about it every single day – at home, in the studio commissary, in his dressing room, on the sidewalk – until he simply wore the actor down. MacMurray felt safe about his acquiescence because Paramount, which had him under contract and had carefully crafted his good guy image, would never let him play a "wrong" role. His trust, however, was misplaced: His contract was up for renewal at the time, and because his friend and co-star Carole Lombard had shrewdly and successfully taught him how to play hardball with the studio bosses, he wasn't the pliable pushover of old. Paramount executives decided to let him play the unsavory role to teach him a lesson. A lesson was indeed taught, but not the one Paramount had in mind. MacMurray made a great heel and his performance demonstrated new breadths of his acting talent. "I never dreamed it would be the best picture I ever made," he said.
Edward G. Robinson was also reluctant to sign on for the role of Barton Keyes, but not for the same reasons as MacMurray and Stanwyck. Having been a star since Little Caesar in 1930, this role represented a step downward to the third lead. Robinson later admitted "At my age, it was time to begin thinking of character roles, to slide into middle and old age with the same grace as that marvelous actor Lewis Stone". It also helped, as he freely admitted, that he drew the same salary as the two leads for f
Double Indemnity (film)