The investigation began in May 2007, when a student died of a drug overdose on the San Diego State campus and police traced the drug back to the ring. The operation intensified when a second student died from a cocaine overdose in a fraternity house in February 2008. As part of the investigation, the authorities said they infiltrated the three campus fraternities and made over 100 drug purchases. They also said that most of the members of the fraternities were either directly involved or were aware that their fraternity brothers were selling drugs.
Members of the Theta Chi, Phi Kappa Psi and Delta Sigma Pi fraternities were arrested on a variety of drug-related charges, officials said. They said that one of the non-students arrested was a documented member of a Los Angeles gang with links to Mexican drug cartels.
http://www.nytimes.com/2008/05/06/us/07student.html?hp