[Catlady]

I just unearthed an old paperback entitled Brief Against Death, by Edgar Smith, a death-row inmate who claimed to be innocent; his case became something of a cause célèbre in the mid- to late 1960s when William F. Buckley Jr. (the conservative founder of National Review) believed he'd been unjustly convicted. Buckley helped him get a new trial and he was eventually freed after a plea deal.

Spoiler:

A few years later Smith committed another crime, was convicted of attempted murder, and was sentenced to life in prison. Smith's protestations of innocence in the earlier case, as detailed in Brief Against Death, turned out to have basically been a con job.