Although we have scant details to go on, I thought that his disappearance went down this way:
Bob was supposed to meet with Randy at Randy's house (since R's mom knew about his visit). Bob got lost or confused about location of Randy's house (witness statement that Bob was stopped, looking around in a different area and told witness he was looking for his friend (house?)) Before arriving or finding Randy's house, something happened. An accident? A mugging? Randy's mom calls Bob's house to report that he didn't arrive.
Anyway, that is my take on the sequence of events. It seems like there are a lot of other ideas as to what was going on that night.
How can we find out more?
You have what I know. It is scant info. I'd like to know if his bow or keys were still in the car. I'd also like to know if the location of where his car was found was a reasonable distance from his tree stand. Too bad his sister isn't here to answer these questions.