Morgan's friend had the keys to the car. Morgan left the arena to smoke. She could have used indoor smoking areas, but she didn't. She knew that there was a no re-entry policy. She was visibly under the influence outside the arena. She had been known to hitch hike, so it was assumed that she was hitch hiking, in part because of a man with his daughter who claims he saw her hitch hiking. I didn't hear of any people offering to help Morgan. Most people keep a distance from someone that is out of it, or under the influence. I'm not aware of any sightings of Morgan on campus.
My understanding is that she voluntarily left the arena. Outside the front doors, she confronted some people and did not make a good impression. She spoke to her friends on her phone and said that she would find her own way home, telling her friend to use her car. She apparently walked through the parking lot towards the sports field. There, she was seen by some athletes. She crossed the Copeley Bridge, and that was the last that she was seen. The following day her cell phone, without a battery, was found in the parking lot of the sports field. Sometime later, her shirt was found in a nearby neighborhood. The shirt was planted. The phone was most likely planted.
Convictions usually rely on circumstantial evidence. There is DNA evidence on her body that identifies her murderer. Jesse Matthew has been linked through forensic evidence to Morgan. If there is evidence that Morgan was in his car - a long shot after 5 years - that will be one more piece of the puzzle.
