She heard a whisper behind her, an echo of the shattered life she had owned. The voices of the dead frequented her daily. They spoke to her in nightmares, and they waited for her waking.
In court, she had been painted as a monster. No, they were the monsters! She had redressed the balance; less bad people in the world to harm people and the taxpayer to fund. She was a hero, and soon everyone would see that.
That was the problem with pleading insanity and pretending to hear voices – nobody believes the truth when you tell it.
This is a mixture of things I grew up around and stories I’ve heard of people faking mental illness in order to get out of prison for GBH, murder etc. I also like the idea of an unreliable narrator.