PALO ALTO, Calif. (AP) — Stanford University officials say hard liquor is now prohibited in undergraduate on-campus parties.

President John L. Hennessy and Provost John Etchemendy announced the new student alcohol policy in a letter sent Monday to all new and returning undergraduates.

The change comes after former Stanford swimmer Brock Turner was convicted of sexually assaulting a woman, after both drank at a campus party. The case caused a national furor when a judge sentenced Turner to just six months in jail.

Hennessy and Etchemendy say the new policy is part of an effort "to build a healthier campus culture around alcohol."

According to the new policy, only beer and wine will be allowed at on-campus undergraduate student parties.

Hard alcohol use will be allowed at parties hosted by graduate students and only in the form of mixed drinks.