The portion of campus sexual assaults that occurs during fraternity house parties is unknown, several experts said, but a 2007 study financed by the Department of Justice found that women who frequently attended fraternity parties were significantly more likely than others to be sexually assaulted. Multiple studies have found that students in fraternities were significantly more likely to have committed rape than non-Greek men; heavy drinking by both sexes, a characteristic of most fraternity parties, was also strongly tied to the incidence of many forms of sexual assault.

Colleges across the nation are grappling with allegations of sexual assault at fraternity houses. Since September, authorities at California State University, San Marcos; Cleveland State; and Kansas have investigated instances of sexual assault at fraternity parties. Late last year, Brown University suspended a fraternity after a female student drank punch spiked with a date rape sedative, after which she said she was sexually assaulted.

At Texas Tech, Phi Delta Theta was suspended last fall for appearing to encourage rape with a “No Means Yes” banner, and in 2013 at Georgia Tech, Phi Kappa Tau was suspended after a member distributed an email titled “Luring your rapebait,” which ended, “I want to see everyone succeed at the next couple parties.”

At the University of Virginia, where a Rolling Stone article about a gang rape at a fraternity has been discredited, fraternities have nevertheless agreed to new limits to how they serve alcohol, including serving beer only in cans and not from kegs, requiring at least one fraternity member to be sober during parties, and disallowing punch.

George Washington, which has had no recent high-profile episodes, features a fairly typical Greek presence: About a quarter of its 10,000 undergraduates belong to 42 Greek organizations, many with rowhouses on the Northwest Washington campus. While students have options for where to imbibe, from dorm parties to off-campus bars, fraternities have a disproportionate presence in campus social life, some students said, mostly because of the free-flowing alcohol.