A retired federal agent is one step closer to a murder trial following a Denton County grand jury’s decision to indict him over a shooting in a Denton City Hall parking lot.  Gary Landers was arrested in early May following the shooting death of a friend’s ex-husband while that couple were exchanging their children in accordance with their child custody agreement.  Landers said he had accompanied the woman because of a history of violence between the couple.  He and the children’s father began to quarrel and then police say Landers pulled a pistol and shot the other man several times.  Landers is a retired law enforcement officer with the Federal Aviation Administration and was legally permitted to carry a concealed firearm.