Murray, KY – A prosecutor says he and federal investigators did nothing improper in advising a key witness about what to say in a Kentucky bid-rigging probe. Assistant U-S Attorney Ken Taylor says the assertion by defense lawyers appears be an attempt to influence public opinion by creating an aura of misconduct in the case. Construction contractor Leonard Lawson, former Transportation Secretary Bill Nighbert and Lawson aide Brian Russell Billings have pleaded not guilty to charges of conspiracy, misapplication of property and obstruction of justice. Defense attorneys argue that a recording suggests that the prosecutor and investigators improperly coached the key witness during the investigation. They want to use the recording in the upcoming trial. The judge hasn't yet decided whether defense attorneys can keep the tape.