So it's now, what, 55 years since the famous mystery of the Sheppard murder? This night before the holiday, or the early hours of the holiday. I have never believed he did it. Wonder why the DNA science of today, that has proven many innocent, or guilty, can't solve this one...

He was later found to be innocent. There is a lot of info on him on line.

There is a lot on-line, but I do not believe Sheppard was ever officially found to be innocent.

On the 50th anniversary of his Mom's death, on July 1, 2004, Sheppard's son said:

"I believe that in the court of public opinion we have shown the certainty of the innocence of my father, Dr. Sam H. Sheppard. But without official state sanction it appears that this case will be a legendary American murder case that goes unsolved."

http://www.samreesesheppard.org/pressrel11.html

I believe that the situation was he was retried and not found guilty (which of course means in the eyes of the law not that he didn't do it) but then a decade or so later evidence showed that he didn't do it but they did not know for sure who did. In 1997 DNA testing showed that there was a third person who was in the area at the time of the murder, again Sheppard could have also been there, but I believe the DNA belonged to a fellow who was a suspect who is presently doing time for another murder (if he is still alive). Since dying I don't think much attention was given to the case outside of the son trying to clear him.

Following the second trial, the theory was put forth that the crime was done by a woman. With 25 or more blows to the head, the murderer was unlikely to be as strong as most men.

This fit in with the "bushy-haired man" that Sam saw, if you think in terms of female hairstyles of that era.
As I recall, the theory extended to the jealous wife of a neighbor Marilyn was seeing, and that man, following his wife to the scene, came upon Sam struggling with the wife and struck him from behind...

This was F.Lee. Baily.s break I believe?

Yup, nothing feels as good as saying F' Lee Bailey!

Sometimes they don't need evidence. Look at the railroading of the West Memphis Three.