Spangler was an actor and dancer.

At the time that she went missing, Spangler had been working at the nightclub Florentine Gardens as a dancer and had also been an extra in a few movies, including When My Baby Smiles at Me, Young Man with a Horn, and Wabash Avenue.

Mother to a young daughter named Christine, the aspiring performer had been in a custody battle with her ex-husband, Dexter Benner. Initially, he was given custody of Christine after painting Spangler as a party girl in court, according to the Los Angeles Times. Later, Spangler was awarded custody of their child.

She was last seen on Oct. 7, 1949.

On the evening of Friday, Oct. 7, 1949, Spangler left Christine with her sister-in-law, Sophie. The Los Angeles Times reports that she told Sophie she was going to meet with Benner about his late child support payment and then go to work on a movie. Spangler lived with her mother, Florence Spangler, who was out of town.

"She came down the stairs and asked how she looked," Sophie told reporters, according to Entertainment Weekly. "She smiled at me, and then her little girl, Christine, asked where she was going. 'Going to work,' Jean answered again, but she winked at me when she said it."

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Her purse was found in a park.

Sophie said that Spangler called to tell her she wouldn't be home until morning, but when Spangler still wasn't home by Saturday night, she called the police.

On Sunday, a worker in Los Angeles' Griffith Park found Spangler's purse. The handle was torn, and the bag contained a note written by the missing actor. "Kirk, Can't wait any longer. Going to see Dr. Scott," it read. "It will work best this way while mother is away."

It was the only trace of Spangler that was ever found.

There are several theories of what happened to her.

Neither the police nor the people in her life knew who "Kirk" or "Dr. Scott" were—or at least no one came forward with that information. According to the Los Angeles Times, the actor Kirk Douglas—the most famous Kirk there was—called authorities from his vacation in Palm Springs and denied that the name referred to him. The two had both appeared in Young Man with a Horn, but Douglas said that he barely knew Spangler.

Actor Robert Cummings reported seeing Spangler prior to her disappearance. He said that she was in a new relationship and told him she was "having the time of [her] life."

The missing woman was also reportedly seen with two men associated with the mobster Mickey Cohen.

Various threads regarding the note and Spangler's whereabouts led to theories that she was killed by the mob, killed during a secret abortion, killed by her ex-husband, or killed by the Black Dahlia murderer, since she shared some similarities with Elizabeth Short, who had been murdered two years earlier.

Police do believe that she was killed—but they don't know by whom.

Entertainment Weekly reported that Rick Jackson, a retired LAPD homicide detective, said the most likely reality is that Spangler was killed. But no one was ever arrested or charged with her murder and no body was ever found.

"Nothing I've ever read would indicate [she skipped town]," Jackson said. "People generally don't do that kind of thing unless there's a motive or a unique set of reasons. Obviously, she cared for her daughter enough to get custody back. It just makes sense that she met foul play. There's no doubt she was dead, and that's why she never surfaced."