Video from that day shows no sign that her car was there, and the way she claims she drove home is physically impossible, authorities told her.
In later testimony, Witness 40 changed her story about some of what she saw and admitted to having gathered some details from news reports. She also gave a different reason for having allegedly been in Ferguson that day, and shared part of a journal that she claimed to have kept.
On the day of the killing, she posted a comment online saying, "They need to kill the f---ing n-----s. It is like an ape fest," the grand jury documents say. (CNN is redacting the "f" and "n" words, but she used them in full.)
My cynical side suspects that this CNN piece was written primarily to get her testimony out there.