He was taken to hospital in a serious condition but died yesterday.
The three murder accused made no pleas or applications for bail today.
Judge Stephen O'Driscoll remanded them in custody to the High Court on April 12. The teenager is remanded in the custody of Child, Youth and Family services.
Before they appeared in court, family members demanded to see their loved ones.
Then in court, Jetson left the dock and lunged at people sitting in the public gallery.
It took six police officers to restrain Jetson as he yelled and resisted being handcuffed.
Outside court, family members and friends took exception to being filmed as they left the courthouse.
Again, police and court security had to intervene.
More police cars rushed to the scene to help disperse the crowd.
Police investigations into the death are ongoing.