The teen is accused of killing his 11-year-old half-brother, Terry Smith Junior. Monday's detention hearing was continued to September 17.
A massive communitywide search effort was undertaken to find Smith. Authorities found the boy's body almost four days after he went missing.
Monday it was not revealed whether the teen will be charged as an adult, but he will stay behind bars at least until his next court date on September 17.
"The judge did make an interim finding of keeping him detained until at least the 9/17 hearing, and that was based on the safety of the public, as well as the safety of the juvenile himself," said John Hall, Riverside County District Attorney's Office.
The judge talked about the 16-year-old already being on probation, and said the boy has a history of violent outbursts.
Still, he did have a number of supporters outside, including friends from high school.
"I can tell you that there's no way, of all the people in the world -- it takes a certain kind of person to hide a body for four days, to lie to law enforcement for so long, and that's not [the suspect]," said Miguel Diaz, a friend of the suspect's.
High-school friends say if the suspect did kill his younger half-brother, he can't be the only one responsible.