After three weeks of trial in a closely watched patent case involving genetically modified soybeans, a federal jury in St. Louis, Mo., took one hour to return a $1 billion verdict against E.I. du Pont de Nemours and Co.

The August 1 verdict ranked No. 3 on The National Law Journal affiliate VerdictSearch’s Top 100 Verdicts of 2012. George Lombardi, who represented Monsanto Co., the plaintiff in the case, said he had an easy story to tell.