There’s little information on the net, and if so, my Google-fu isn’t working well with it. The facts as I know them:
Dog was convicted of the murder of Jeremy Oliver in 1977, but was paroled two years later.
He maintains his innocence, but so do most people.
What were the details of the murder case, and what convinced a parole board that parole after two years was OK?
Little information is right. The only scrap I could find was this, which you probably know already, but just in case:
Chapman describes the crime in his autobiography, which I am pained to admit I have read. The story he tells is basically the one **aldiboronti **recounts. He and a friend went to rob a drug dealer, and the friend ended up shooting and killing the guy. He was convicted of being an accessory because he was present, although the state never argued that he participated in the actual murder. Chapman was sentenced to five years and paroled after 2.
Wanted to add that while some sources (like wikipedia) say that Chapman maintains his innocence, he actually acknowledges his role in that particular crime. He;s also pretty open about his general disregard for the law when he was running with the motorcycle gang.