Charges include permitting drug abuse, hazing, tampering with evidence, drug trafficking, obstructing justice, assault, and reckless homicide. The university expelled the Sigma Pi fraternity last April. Seven of the suspects were in the fraternity. The family of 18-year-old Collin Wiant sued the frat, saying he died of asphyxiation last year after ingesting nitrous oxide provided to and forced on him. The frat denied those allegations.