State attorneys in Minnesota's tobacco trial showed industry memos that suggest companies knew low-tar cigarettes could be as dangerous as full-flavored cigarettes but never told the public. Attorneys introduced the memos during cross-examination of defense witness--David Townsend. Townsend is vice president of product development at the nation's second largest cigarette maker--R-J Reynolds. Minnesota Public Radio's Elizabeth Stawicki reports: A 1990 RJR memo said low-tar cigarettes aren't what they claim to be; and advertising ultra low-tar is misleading. It said smokers tend to smoke until they reach their individual requirement for nicotine by inhaling low tar cigarettes more deeply or subconsciously blocking vents on filters with their fingers or mouth.