A gunman killed a 31-year-old Queens man early Monday and shot a 24-year-old man in the back, police said. The gunman shot the men in front of a building on 124th St. near Liberty Ave. in South Richmond Hill at about 3:25 a.m., officials said. Paramedics rushed the men to Jamaica Hospital, where the 31-year-old man died. The 24-year-old man was in stable condition, officials said.No one has been arrested. Neither man was immediately identified.(nydailynews.com)…[+]