This was first reported at Huffington Post, then ABC news and now other news outlets are picking it up.
One of the first things Huckbee did as govenor was to push for the release of a convicted rapist, Wayne DuMond. The guy had raped a distant cousin of Clinton. While waiting for the trial, someone hogtied him and castrated him. He was sentenced to life in prison and then the Lt. Guv, Tucker, commuted his sentence to 39 years (Clinton recused himself), which eventually made him eligible for parole.
All of this guys victims (he had priors I think) pleaded with Huckabee not to release him. Right-wing christian conservatives in the state pushed Huckbee to pardon the guy. It's unknown why they were pushing for his release so hard, but there is speculation this was a slap at Clinton. Instead of pardoning the guy, Huckabee pushed the parole board to parole him and within a year DuMond had raped and murdered a mother of 3 and was suspected of murdering another woman. He died in prison before he could be tried on the second murder charge.
http://www.latimes.com/news/nationworld/nation/la-na-huckabee8dec08,0,5697447,full.story?coll=la-home-nationHuckabee now denies that he pushed the parole board, but the board members say otherwise and their are copies of all the letters victims wrote to Huckabee asking him not to parole him.
This may be Huckabees Willie Horton moment.