If the suspect was studying criminology, then he's a complete incompetent, if guilty. Going to another state wouldn't evade them for long.
As I said before, Idaho is in/near the Rocky mountains, where a competent mountain man can easily disappear and never be found.
The innocence of executed prisoners is beside the point. The death penalty was never about justice, it's to indulge latent blood lust in the public. Witches, sacrificial victims, murderers, make it seem like a good thing and human nature takes care of the rest.