SALEM – Prosecutors in the Joseph R. Graciale III, trial were forced to drop the first-degree murder charge against him on the eve of the trial after their key eyewitness invoked his Fifth Amendment privilege.The 30-year-old Lynn man was charged with shooting a man in the head in 2008, killing him over a marijuana deal.?It feels good to be a free man. I was innocent,” Graciale emphatically stated as he walked out of Salem Superior Court Monday morning and was greeted by numerous family members.Jury empanelment was scheduled, but before that a hearing was held concerning the government?s key eyewitness, Yared Molina Rios, 25. He took the stand and told Judge David A. Lowy he was using his Fifth Amendment privilege to not testify at the trial.Defense lawyer David Grimaldi pointed out several reasons why his client should not testify. He said that his client was present when the victim, Raphael Andino, 43, earlier had purchased one pound of marijuana from a home in Lynn, and that his client was present during a fight between Andino and Graciale before the June 8, 2008, shooting. He added that his client had discarded a BB gun on behalf of Andino and had made multiple inconsistent statements to police.Upon hearing the judge?s decision, Assistant District Attorney Gerald P. Shea then informed Lowy that he needed time to discuss the case with District Attorney Jonathan Blodgett before jury empanelment could proceed.Shea later informed the judge that prosecutors were dropping the first-degree murder charge against Graciale, because they did not have a case.?He (Rios) was the only eye-witness we had that saw the crime take place. He was the main witness,” Shea commented following his decision.Andino, of 9 Surfside Road, Lynn, was shot in the head at approximately 1 a.m., in the parking lot on Johnson Street, near Lynn City Hall.Rios was present with Andino at the time of the shooting.Investigators learned that Graciale had contacted Andino to sell him some marijuana. Following a fight at the first meeting, the two rescheduled the meeting. When Graciale arrived at the lot by car, shots were fired and Andino was struck in the head from a single bullet.Authorities never recovered the gun used in the shooting. Graciale fled and was arrested the following day in Salem.?My client proclaimed his innocence since Day 1. It?s been a long two-and-one-half year road. Mr. Graciale is happy to be going home for the holiday,” said defense lawyer Michael T. Phelan of Lynn.Phelan explained that Rios had told three or four versions of the story to authorities and that a jury would not have found him credible at trial.Graciale was indicted on a charge of first-degree murder, which carries a life sentence, by an Essex County grand jury in September 2008 and has been held without bail at the Middleton Jail since being arraigned.His jury trial was expected to last two weeks.Rios, of Jamaica Plain, is no stranger to the court system. He was convicted in Salem Superior Court of making a bomb threat and assault and battery on a police officer in Lynn on Nov. 25, 2008. He received a split term of one-year in jail, with all but 90 days suspended and placed on a year of probation