Judge Robert Philyaw made the decision in Hamilton County Juvenile Court on Thursday morning, after hearing all of the state's evidence against the teen.
Police say Sims burst into a College Hill Courts apartment and opened fire, killing 20-year- old Talitha Bowman and injuring two others, including 1-year-old Zoey Duncan.
Survivors identified Sims, who fled. Sims was briefly placed on a Tennessee Bureau of Investigation list of the state's most-wanted fugitives, and was arrested days after the shooting in Knoxville.
Sims is charged with first-degree murder, and several counts of attempted first-degree murder. He will be transferred to the Hamilton County Jail on a bond of $1.6 million.