Infamous Boundaries on Instagram: "In 1978, 15-year-old Mary Vincent climbed into what she thought was a safe ride on a California highway — and stepped straight into a nightmare. Her driver, 50-year-old Lawrence Singleton, attacked her with unimaginable brutality, and when he feared she might escape, he took a hatchet and severed both her arms. He dragged her to a remote culvert, threw her over the edge, and drove away believing he had erased a witness forever. But Mary refused to die in the pl