CHICAGO — After a nearly three-month trial and four days of closing arguments, a federal jury finally began deliberating late Wednesday in the racketeering case of six purported gang members charged with carrying out the brazen 2020 murder of drill rapper FBG Duck in the Gold Coast. The jury of five men and seven women, who have remained anonymous due to security concerns surrounding the case, were sent back to the jury room at about 5:25 p.m. Wednesday, but almost immediately told the judge they wanted to leave for the day. They are expected to resume Thursday morning. Prosecutors alleged the…