When a freshman at San Diego State University (SDSU) died of a cocaine overdose last May, the campus police chief decided to pursue a full-scale investigation. In December, he summoned undercover agents from the federal Drug Enforcement Administration to pose as students and roam the campus in search of illegal drugs. According to college president Stephen L. Weber, drug use is a concern on virtually every campus and SDSU has taken an action to confront it directly. Such a sweeping drug investigation, however, raises high-stakes questions. When should a university punish instead of educate? Does inviting undercover federal agents onto a campus strain an administration's relationship with its students? Will trying to solve a problem make an institution notorious for having it? San Diego State officials have no regrets. "It's not just that we were looking at a problem of degree and seeing more drug usage than previously," Mr. Weber said in an interview with "The Chronicle." "We're talking about what is at least now alleged to be drug trafficking on campus, things like loaded shotguns and semiautomatic weapons." Some students and their families have applauded San Diego State's crackdown and "zero tolerance" policy, while other students have expressed a feeling of betrayal.