Parties in a homicide retrial debated the credibility of the prosecution’s key witness in closing arguments on June 3 before DC Superior Court Judge Danya Dayson. Alonzo Brown, 29, and Naquel Henderson, 28, are charged with conspiracy to commit a crime of violence while armed, first-degree murder while armed, two counts of assault with intent to kill while armed, and three counts of possession of a firearm during a crime of violence for their al…