State's attorneys in Minnesota's tobacco trial introduced memos that show Philip Morris identified a cancer-causing chemical in cigarette smoke during the 1960's but didn't try to remove it until 20 years later. Attorneys for the State and Blue Cross introduced the memos during cross examination of a Philip Morris senior scientist--Clifton Lilly. Minnesota public radio's Elizabeth Stawicki reports: Attorneys showed the jury a Philip Morris memo from the early 60's in which a scientist wrote cigarette smoke contained a cancer-causing chemical. another memo introduced said the nation's number one cigarette maker didn't try to remove the chemical until 20 years later. One senior scientist who received that memo was Clifton Lilly now a vice president for developing new technology.