Kaidi Yuan and Ashley Zhang

New details about Donna Heinel, the senior associate athletic director who prosecutors say was a key conduit in the Varsity Blues scheme, shed light on just how expansive her role within the athletics department was -- and on whether USC monitored her activities closely enough.

Additional employees at the University of Southern California were involved in the "Varsity Blues" admissions scandal beyond the four indicted so far, according to court documents and prosecutors' statements.