SALEM – A Superior Court judge dismissed a narcotics case against a Lynn man after his attorney successfully argued that the information presented to the grand jury was not sufficient to indict his client.Prosecutors charged Arthur Poisson, 33, of Lynn, with trafficking over 28 grams of heroin stemming from the sale of heroin to a confidential informant in front of 59 Clarendon St. in Lynn on Sept. 2, 2009.Wednesday morning in Salem Superior Court defense lawyer Russell C. Sobelman challenged the indictment against Poisson, arguing that the grand jury presentation by the commonwealth failed to properly identify his client as an occupant in a silver Dodge Durango during the drug deal.In addition, the confidential informant told authorities during a photo identification procedure that he recognized Poisson, but did not specifically identify him as one of the occupants in the vehicle who sold him the heroin.Judge John T. Lu agreed with Sobelman and dismissed the charge against Poisson.However, Poisson, who has been held in lieu of bail, was not released. He currently is serving another sentence at the Middleton Jail on drug charges.