The teen appeared at a San Leandro courtroom as his family gathered outside.
He faces four counts, including murder and gun charges.
Prosecutors said he shot his sister January 23 in their Franklin Street apartment after an argument. The teen's defender said it's been difficult for the family to deal with.
"Well they're trying to hold it together. You know, this is a family who lost their daughter. This is a family who is in crisis. They have a son who faces very serious charges. And as anyone can understand, they're dealing with a lot of grief and emotion right now," defense attorney Adante Pointer said.
The sister who was killed, 17-year-old Justice Toliver, leaves behind a 3-year-old daughter.
For details on an online fundraiser for Justice and her child, click here.
