Jason Contreras took the oath at a ceremony at Aurora City Hall. He was a police officer in Plano, Ill., for more than a year before moving to the Aurora Police Department.
Contreras was only 3 years old when his brother, Nico Contreras, was killed by a stray bullet while the young boys were sleeping at their grandparents' home in 1996. Nico was killed two days after his sixth birthday.
ABC7 Eyewitness News partner The Daily Herald reports murder charges in the cold case could finally be announced this week. Investigators believe another family member may have been the intended target.