LAWRENCE – A Lawrence Superior Court jury convicted an elderly Lynn man of possessing child pornography Tuesday afternoon.Neal Pierson, 72, of 71 Orchard St., Lynn, went on trial on a charge of possession of child pornography.Jurors had the case for about two hours before reaching their verdict.Judge Garry V. Inge delayed sentencing Pierson until next Monday at 2 p.m.In the meantime, Pierson will remain free on $1,000 cash bail until his punishment is handed down.Assistant District Attorney Jean M. Curran successfully presented evidence to a jury that Pierson subscribed to a pornography distribution agency in which he received two child pornography videos through the mail and paid for it with a money order.He didn’t realize, prosecutors said, that the a U. S. postal inspector was watching the agency.Investigators arrested Pierson when he received the package on Sept. 9, 2009.The videos depicted children in lewd exhibition, police said.Pierson did not take the stand in his own defense.The defense argued that his client was innocent, but the jury was not swayed.The two-day trial began yesterday in Lawrence Superior Court.