Where a defendant fails to preserve an issue by objecting at trial and raising it in a post-trial motion, he must seek review under the plain error standard and demonstrate both that the evidence was closely balanced and that the alleged error prejudiced him at trial.The 1st District Appellate Court affirmed the decision of Cook County Circuit Judge Thomas V. Gainer Jr.On Sept. 11, 2010, Chicago police officers Aaron Davis and Tiawansa Davis were on patrol when they were approached by Fallon Jackson, who was having a …