Her career was over.
When she was corralled by the house dicks, she was reportedly armed with a fake pistol and a handkerchief soaked in chloroform.
For the first three days, while she was locked up in a holding cell, she insisted that her name was "Josephine Rust". It was her husband who had planned the robbery she said, but he backed out because he didn't have the guts, and so she did it herself. A real tough moll, she was.
But as the days passed, so did her resolve. She changed her story to a more sympathetic one, and decided to take her chances with a jury.
She was offered a pre-trial sentence of probation if she pleaded guilty; she was innocent, she said, she wouldn't take it.
"What was your rationale?", the Judge asked her.
Now the story was that she had gone to Mrs. Bobbe for "financial aid", she said.
And the toy pistol?
It was a cigarette holder, and the chloroform was for her only, bought earlier when she had contemplated killing herself. She had been here, alone in the City of Big Shoulders, for eight months with only a few hundred dollars to her name, now spent, and she was starving, and broken in body and spirit; couldn't they see that? Why won't they help her?
In a surprise, her parents and sister arrived.
Joan La Costa, the "premier French woman driver" was the daughter of Mr. and Mrs. W.M. Carver of Memphis, Tennessee. Her actual first name was Marion.
What could have persuaded her to leave a city where she had immediate and extended family and friends, and light out for Chicago? Was it impossible for her to be "Mademoiselle Joan La Costa" in the Tennessee house of her parents, Mr. and Mrs. Carver? She had recuperated, socked her cash and limped out of her hometown as soon as she was able.
But now this, and she was stuck as Marion Carver again.
The story started to shift once more.
After admitting to the police that, yes, her name was Marion Carver, nee Joan La Costa, she tearfully confessed what she now professed was "the truth".
"I have so many friends who knew me at that period that I cannot say anything about it," she said of her former glamorous life, "I wonder what they think of me now?"
Story number three soon tumbled from her lips...
She confessed that she had knocked at the door of the apartment of Mrs. Bobbe in the Chicago Beach Hotel on Thursday night, a cigarette case resembling an automatic in her hand.
"Don't scream, or make a noise and you will be safe," she told Mrs. Bobbe, who had opened the door while draped in $20,000 worth of jewelry.
Instead of obeying, Rebecca Bobbe showed some guts herself, and fought back. Her cries brought forth her maid and other tenants.
Why had she done it, she was asked?
According to the newly penitent Miss La Costa, she had come to Chicago just a few days ago, with $1400 that she had marked for flying lessons. She promptly lost it all at the horse races.
Meeting an acquaintance by the name of Hyman Bobbe, she told him of her plight. He sympathized, and wished he could help, but didn't have the money like his brother Joseph did.
Really? And how much money did his brother have? They were loaded, he said, and lived in the nicest Hotel in town at the Chicago Beach...
On November 9th, the sentence was finalized and reduced to a year under probation, and a grateful Joan said to the judge, "I'm going to be good. I'm going to take up aviation and hope to become a commercial pilot. I think it'll be better than auto racing and more thrilling." Just a few months before, Amelia Earhart had crossed the Atlantic by flight. Perhaps she could recast herself again, become another inspirational incarnation, this time as an aviatrix.
Three years later, it was reported that she'd married a meat seller named Joe. The records show that this man, Joseph Maurer, wedded a woman named "Marion Joan Martins" in October.
Had she finally surrendered her exotic French name when she surrendered her dreams? "Mlle. Joan La Costa" was the famous, exciting race car driver, "Josephine Rust" was the bad girl "armed" robber.
Marion married a meat salesman.
Joan then slipped away from us, retreating to the anonymity of the pre-internet, avoiding the ever-lasting infamy that she most certainly would have been unable to escape today.