Just my two cents worth, as someone who has read everything I can find on Ted Bundy trying to match him up with other missing women, but I doubt he took Laurie. He normally was out of his car when he persuaded women to go along with him, and often used a ruse such as a cast on his arm or leg, in order to get them to go to his car. I think he enjoyed the cat and mouse game of setting up his lie and getting a woman to go along with him. He might have offered a woman a ride if he saw her walking but it doesn't fit his usual pattern. Given that someone saw Laurie in a field with a man, then again riding in a vehicle, I would discount Bundy completely if those sightings are considered reliable.
I think, in regard to Bundy's credit card receipts, they were able to set up a timeline of what time of day he was in what area. Maybe he just couldn't possibly have gotten to Spokane at the time of day Laurie was taken based on a credit card receipt from another area. They must have had pretty concrete evidence to have ruled someone like Bundy out.
Just my opinion, but I would not be surprised if whoever took Laurie knew her. She may not have known him, or at least not personally, but he may have seen her around or even had his eye on her.
I sure hope the family gets some answers on this. I often think of these cases, so very far in the past now, and wonder how the families have coped with not knowing what happened to their loved one or where their remains are.
