Bail has been denied for a black teenager charged as an adult in a weekend triple murder, including one victim who was picking up pastries for her 2-year-old’s birthday party

African-American Nicko Grayson, 17, scowled when he appeared in court and was scolded by Judge Maria Kuriakos Ciesil when he turned his head away from the bench and began muttering something under his breath. Grayson has been charged with first-degree murder in the slayings of Chanda Thompson, Shawn Russell and a friend, Cortez Champion, all 21. Cook County prosecutors said that the victims were sitting in a car in a parking lot when a gunman emerged from an alley dressed in dark clothing and opened fire. Thompson had just purchased a cake for her daughter’s birthday party scheduled for the next day, Assistant State’s Attorney Jamie Santini said. “A witness watched as the defendant walked around the car firing his gun at the unarmed victims multiple times,” Santini said. “The witness then saw (Grayson) reach into the car and fire several more times at point-blank range.” All three victims were struck multiple times in the head, neck and back. Police recovered 16 spent 9 mm shell casings and four fired bullets from around the car, according to Santini. Prosecutors said that a witness heard gunshots, saw Grayson running and then enter a silver-colored car. The witness followed the car and saw Grayson and another person jump out of the car and run, while a third unidentified suspect drove off, according to Santini. Detectives used witness descriptions of Grayson to identify him in a photo array. After his arrest he was identified in police lineups as the gunman, Santini said. Grayson has an extensive juvenile record that began with a burglary conviction in 2008 when he was 14, Santini said. Over the next three years, he was convicted twice more of burglary as well as discharge of a firearm and violating his probation. He was paroled from a juvenile detention center following his latest conviction in April 2011, Santini said.