WEST PALM BEACH, Fla. -- An attorney for the widow of a middle school teacher gunned down by a student argued before an appellate court Tuesday that the gun distributor was negligent in selling the cheap weapon and should be held liable.Attorney Edna Caruso said federal officials told Valor Corp. for years that its .25-caliber Raven handgun was frequently used in crimes and that the company had a legal responsibility to make the weapons safer."Here we have a distributor that is known to distribute crime guns. It's been warned for years and years and years," Caruso said. "It says, 'I...