I've recently read the book, Murder In The Mountains, and I recommend it for anyone interested in the story because for one thing, it's the only reference/source I'm aware of or have access to for any information about the case.
Two men were charged in the crime; they were tried separately and after the first trial ended in a not guilty verdict- which I think was a correct verdict- charges were then dropped against the second man (also rightly so, I think).
At the end of the day, I think it's one of those cases where investigators very likely made contact with the perp- I know it often goes that way, regardless, but in this case, I don't think the perp was even considered as a POI.
A very interesting aspect of the book is that it includes insight from current investigators who were consulted by the author.