They're charged in the October 2009 attack of a 16-year-old girl outside Richmond High School after a homecoming dance.
A rare dual jury trial is scheduled for 22-year-old Jose Montano and 20-year-old Marcelles Peter.
The two juries will hear most of the witness testimony together, but deliberate separately.
In all, eight people were charged. Some have already been sentenced and other are facing upcoming trials.