I guess I'm negative on a prosecution in Betsy's murder, although finding a logical conclusion might be nearly as good. If it was a lone killer, short of a confession, I don't know if LE could find enough evidence to prosecute. The case is nearly 40 years old, memories have faded, and people have died. No one saw the killer, who is, most likely, around 60 years old. I think there are people who take secrets to their graves, and Betsy's killer may be one of them.
I don't think you're negative at all -- I think like me you are realistic. The odds of them being able to prosecute without the murder weapon and without a witness are unlikely. However, stranger cases have been prosecuted.
Just saw one on Dateline the other night where a guy was convicted of a murder of a 14-year-old which had originally been ruled a natural death, simply because his mom on her deathbed tipped police that she always thought her son was involved, and he confessed that he was out on the golf course with her that night. He never confessed to the murder, mind you, just that he was present.
The police had discarded most of the original evidence -- no clothing, no DNA, no nothing.
It was successfully prosecuted 20 years after the fact and he was convicted on the simple fact that he told police "Yes, I was there with her that night."
It was a real screw-up by the police from the start -- the girl had been dragged and hastily covered with some branches and twigs, her clothes were ripped, and the coroner ruled that she had died of a genetic heart condition -- and, of course, didn't want to inconvenience the golf course, so she dragged herself off the course and buried herself in brush in the woods. :waitasec:
The strength of the mother's tip was enough to get police to exhume the body, do a new autopsy, etc., etc., and get the ball rolling. But no one saw it.
So I keep holding hope that the police in this case -- who have partial prints, who may have DNA, who have hundreds of interviews on file, etc., might have enough to prosecute, or get a confession from the right suspect under the right circumstances.