Coleen Gray and Tyrone Power in “Nightmare Alley” (1947). (Rex Features via AP Images/AP)

“I was always the goody-two-shoes,” actress Coleen Gray often said, “but I wanted to be a sex symbol.” She had grown up on corn and dairy farms in the Midwest, and her doe-eyed beauty and unaffected style drew the notice of Hollywood directors.

She won featured roles in much-admired crime dramas of the late 1940s and 1950s, notably “Kiss of Death,” “Nightmare Alley” and “The Killing” — but not, to her regret, as a femme fatale or hard-bitten dame.

Instead, film scholar Eddie Muller wrote in his book on the film noir genre “Dark City Dames,” Ms. Gray’s most frequent role was “the slumming angel of reason and redemption, ably wrestling straying men away from the precipice.”

Ms. Gray was 92 when she died Aug. 3 at her home in the Bel Air neighborhood of Los Angeles, said a friend, David Schecter. The family did not disclose the immediate cause.

If Ms. Gray did not become a household name, it is probably because she was eclipsed by the general thrust of film noir and its emphasis on cynicism, toughness and sometimes outright sadism.

As the force representing innocence, salvation and blind love — whether for victimized parolee Victor Mature in “Kiss of Death” (1947), thorough heel Tyrone Power in “Nightmare Alley” (1947) or heist mastermind Sterling Hayden in “The Killing” (1956) — she seldom had the most memorable scenes.

Ms. Gray’s rise was sudden. She graduated in 1943 from Hamline University in Minnesota, where she had been involved in theater, followed a boyfriend to Los Angeles and swiftly won a seven-year contract at Twentieth Century-Fox.

After four years of uncredited minor parts, she was formally introduced to movie audiences in “Kiss of Death.” She narrates the film warmly, telling of her marriage to Mature, a crook who turns state’s evidence and is preyed upon by a cackling, cold-blooded killer named Tommy Udo.

But Richard Widmark, in his screen debut as Udo, stole the show from its nominal stars and garnered an Oscar nomination.

In the film’s most riveting scene, he gleefully ties an old lady (Mildred Dunnock) into a wheelchair and shoves her down a staircase. Ms. Gray’s real-life husband at the time, Rod Amateau, a wannabe director who was then moonlighting as a stuntman, had the burden of taking the tumble.

“Mildred Dunnock starts down the stairs,” she told Muller, “but Rod Amateau finishes the trip.”

“Nightmare Alley” cast Power against type as an amoral carnival roustabout who steals a mentalist’s technique. Ms. Gray runs away with the handsome Power, becoming his loyal wife and accomplice. Their phony mentalist act becomes a top nightclub attraction, but a turn of fortunes — including his deepening alcoholism — lands him back at the carnival as a sideshow geek who bites heads off live chickens.

The film was not a hit. But over the decades, “Nightmare Alley” reaped renewed interest among film devotees for its hard-boiled dialogue and bleak portrayal of an opportunist who gets his just deserts. Writing in the New York Times in 2000, film critic Elvis Mitchell called Ms. Gray, who must balance avarice and conscience, “luminous.”

Meanwhile, Ms. Gray went on to a variety of parts: as the love interest of John Wayne in the western “Red River” (1948), warbling with Bing Crosby in “Riding High” (1950) and playing a graveyard-shift nurse who succumbs to drug smuggling in “The Sleeping City” (1950) opposite Richard Conte.

By that time, with her star on the wane, Twentieth Century-Fox had dropped Ms. Gray’s contract. She spent the next several years cobbling together freelance work in grade-B crime dramas such as “Kansas City Confidential” (1952) and “Las Vegas Shakedown” (1955) and westerns including “Arrow in the Dust” (1954) and “The Black Whip” (1956).

Her last film of enduring regard was “The Killing” (1956), a masterly early showcase for director Stanley Kubrick. The drama focused on a meticulously planned racetrack heist and the gang members whose various weaknesses complicate the crime. Ms. Gray’s is her desperate attachment to Hayden, to whom she tearfully confesses: “I’m no good for anybody else. I’m not pretty and I’m not smart, so please don’t leave me alone anymore.”

Increasingly, Ms. Gray turned to guest roles on TV series such as “Perry Mason,” “McCloud” and “Days of Our Lives.” She also spoke candidly about some of the more-ridiculous roles she took. Topping the list, she said, was “The Leech Woman” (1960), a horror film about a scientist’s aging wife who siphons fluids from men’s brains to regain her youthful looks.

“No matter the part,” she told Muller, “I always went at it with complete sincerity. It was a lot of fun making that one. We blew a lot of takes because we were all laughing so hard.”

Ms. Gray was born Doris Bernice Jensen in Staplehurst, Neb., on Oct. 23, 1922. She described her childhood, mostly in Hutchinson, Minn., as cheerless and isolated. She found escape in Hollywood fan magazines, which sparked her ambition to attain movie fame.

Her first marriage, to Amateau, ended in divorce. Her second husband, business executive William C. Bidlack, died in 1978 after more than 25 years of marriage.

The next year, she wed Joseph “Fritz” Zeiser, with whom she participated in Charles W. Colson’s Prison Fellowship Ministries. Zeiser died in 2012.

Survivors include a daughter from her first marriage; a son from her second marriage; two stepsons; 10 grandchildren; and four great-grandchildren.

For much of her life, Ms. Gray was devoted to conservative and evangelical causes, including promoting prayer and Bible reading in public schools in the 1960s.

Reflecting on her career, she told the Los Angeles-based movie blogger Laura Grieve: “I didn’t like being a sweet, wholesome type. I wanted to be sexy. I wanted to be evil and do all those juicy parts. I realize now that the good Lord was protecting me. Better to stay where you are and be good at it.”