After Ron Williamson's trial? (There are several trials referred to in the book- not sure just what you mean.) However, in the Author's note at the end of the book, Rogers is said to be an investigator for Bill Peterson (still the DA in Ada, OK, as of July 1, 2006); Smith retired from the police in 1987 and died in June, 2006.
I'm not just sure what you're asking... a lot happened after 'the trial'- the end result was that Ron Williamson and Dennis Fritz, both wrongfully convicted and subsequently exonerated, were free men. Ron was not ever able to really overcome his addictions or get his various mental problems under control. He died Dec 4, 2004. Dennis managed to pull his life together and (again, according to the author's note) is doing OK. There were other cases mentioned and followed in the book. Two of those men, Tommy Ward and Karl Fontenot, are still serving life sentences for crimes there is almost no way they could be guilty of. Another man, Greg, was freed, also because of being wrongfully convicted.
What happened to me ('after the trial'- or rather after reading the book)- my already waning faith in the criminal justice system in our beautiful land is nearly dead. And, I would say that I can hardly find it in me to feel that the death penalty is OK...