I found this article that talks about the Charley Ross case and some other cold cases, Richard Cox and Ambrose Bierce. The article has several inaccuracies. It spell’s Charley’s name “Charlie” when his family always spelled it “Charley,” gives the place of the kidnapping as Atlantic City, New Jersey (in fact it was Germantown, Pennsylvania; Charley’s mom was, however, visiting Atlantic City when he was abducted) and says:
[T]he two main kidnappers were killed during an attempted armed robbery, and a third man was sent to jail. But that third man would never admit to the crime and spent most of his life in solitary confinement rather than take a seat in the electric chair.
Not so. A third man was sent to jail, yes, and would never admit to his role in the kidnapping, but he didn’t spend the rest of his life there — just six years — he wasn’t in solitary and there was no danger of him being electrocuted. To begin with, he wasn’t charged with a capital offense. Also, the electric chair wasn’t used in executions until 1890. Before that, mostly, they hung people.
The article’s author is merely quoting from a book on the subject, so I guess it wasn’t really his fault but his source’s. But he could have checked on these things.