Police say 18-year-old Philip Dhanens drank a large amount of hard liquor before fraternity members found him unconscious.
This weekend all Greek activities have been postponed at Fresno State.
Fresno police say they've interviewed 40 people as they work to track down how Dhanens got the alcohol and who bought it.
Investigators are also working to find out what care was provided to those pledges who were drinking large amounts of alcohol.
Greek Life Coordinator Eddie Dominguez says all new pledges go through an orientation class which includes information about drinking, but fraternities and sororities off campus are not policed by school officials.
"We are not in a position where we make it a point to be in attendance at social events. They are privately owned properties and the houses are many times owned by alumni corporations of that organization," Dominguez said.
Earlier this week hundreds attended a candlelight vigil to honor Dhanens. The Bakersfield native had only been away at Fresno State for a few weeks before his death.