Nuts
(1987)

Several outcomes are results of the test trial:

• It turns out that Arthur (Karl Malden), Claudia's (Barbra Streisand's) stepfather, abused her sexually from her childhood, all the way up to her late teens, which catapulted her subsequent chosen lifestyle, and also explained her failed marriage.  Moreover, since her mother Rose (Maureen Stapleton) was always drunk, she preferred to keep the situation under the rug, rather than facing it and help her daughter.
• Claudia murdered client Allen Green (Leslie Nielsen) out of self-defense, because he tried to rape her.
• Claudia effectively -and very eloquently- proves on trial that she was not insane, neither at the time of the murder, nor at present; and that she wishes to actually be processed, to prove everyone that she is a sane, harmless person, albeit an extravagant, high-class hooker.  She also forgives her mother, and gets her defending lawyer Aaron Levinsky (Richard Dreyfuss) to like her, and be willing to defend her in court.

Eventually, Judge Murdoch (James Whitmore) rules that she would be standing trial for murder within a month.  This rejoyces her, and she walks out of the courtroom, free.  In the street, she steals a scarf from a passing cart and puts it on, whilst a man passes next to her hollering and rambling incoherencies; she looks at him in pity and raises her hands high, like saying: "And they wanted to make ME nuts!".

The movie ends with title cards stating that she was processed and succesfully acquitted.
 

Thanks Dr Mat!