The first of five men charged with murder in the shooting death of a Lawrence man, which prosecutors have called a case of retribution, has been acquitted. On Wednesday, a Lawrence Superior Court jury found Thomas Castro not guilty in the January 2009 slaying of Robert Gonzalez. Prosecutors said a dispute broke out in the early morning hand one of the five people charged in the shooting lost a tooth. Authorities said in court that later that day, Gonzalez, who was 20, was killed as he was driving a minivan as retribution for the man who lost a tooth. Trials for the other four defendants are pending.