NEW : Booker , Wednesday , surrenders in schoolyard shootings case . NEW : Boy , 20 , taken into custody Wednesday night . College students forced to kneel against wall , shot in head . The four friends , ages 18 to 20 , were shot while listening to music at the schoolyard . Slayings shocked New Jersey , Newark , where street violence is common .
NEW : Booker , Wednesday , surrenders in schoolyard shootings case . NEW : Boy , 20 , taken into custody Wednesday night . College students forced to kneel against wall , shot in head . Slayings shocked New Jersey , Newark , where street violence is common .