His cousin, Patricia Glores, says the family doesn't understand why he was targeted.
"He never got in trouble. He was always kind but we think with all the gangs going on, they thought he was part of one. He never got into any trouble. He wasn't in any gangs," said Patricia Flores, victim's cousin.
Investigators believe the gunman is in a gang. But they say Roky Uriostegui was not a known gang member. In fact, his family says he had just transferred to Kelly High School to avoid the gang members at his old school.
"He was a good kid, basically. He never was with bad people or nothing like that," said Lizette Hernandez, victim's friend.
"He was a good kid to be going around, playing with people," said Marco Patino, victim's friend.
Police are reviewing video from several surveillance cameras on nearby buildings.
Uriostegui's family is looking for answers and hoping the teen's killer will be caught soon.
"He was shot three times, through the back. We don't know exactly what happened yet. I don't know if it was a drive by, somebody driving or somebody walking, we don't know," said Glores.
Uriostegui is the second Chicago Public Schools student killed by gunfire in 2008 and the tenth of the current school year.
Police do not have any suspects in custody.