A Jamaica Plain man pleaded not guilty Wednesday in the killing of Evens Archer. Johnnie Bonnie, 22, pleaded not guilty to all four counts against him, according to the Herald. Archer, 17, was gunned down at a South End party on Castle Court. Prosecutors aim to prove Bonnie was the man who fired one shot into the back of Archer's head. It was three weeks before Archer, a Dorchester resident, died from his injuries, prosecutors said in a statement.