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President Obama shone a light Wednesday on a college sexual assault epidemic that is often shrouded in secrecy, with victims fearing stigma, police poorly trained to investigate and universities reluctant to disclose the violence.

A White House report highlights a stunning prevalence of rape on college campuses, with 1 in 5 female students assaulted while only about 1 in 8 reports it.

"No one is more at risk of being raped or sexually assaulted than women at our nation's colleges and universities," said the report by the White House Council on Women and Girls.

Nearly 22 million American women and 1.6 million men have been raped in their lifetimes, according to the report. It chronicled the devastating effects, including depression, substance abuse and a wide range of physical ailments such as chronic pain and diabetes.

The report said campus sexual assaults are fueled by drinking and drug use that can incapacitate victims, often at student parties at the hands of someone they know.

Perpetrators often are serial offenders. One study cited by the report found that 7 percent of college men admitted to attempting rape, and 63 percent of those men admitted to multiple offenses, averaging six rapes each.

Obama, who has overseen a military that has grappled with its own crisis of sexual assaults, spoke out against the crime as "an affront on our basic decency and humanity." He then signed a memorandum creating a task force to respond to campus rapes.

Obama said he was speaking out as president and a father of two daughters, and that men must express outrage to stop the crime.

"We need to encourage young people, men and women, to realize that sexual assault is simply unacceptable," Obama said. "And they're going to have to summon the bravery to stand up and say so, especially when the social pressure to keep quiet or to go along can be very intense."

Obama gave the task force, comprised of administration officials, 90 days to come up with recommendations for colleges to prevent and respond to the crime, increase public awareness of each school's track record, and enhance coordination among federal agencies to hold schools accountable if they don't confront the problem.

Records obtained by The Associated Press under the federal Freedom of Information Act illustrate a continuing problem for colleges in investigating crime. The documents include anonymous complaints sent to the Education Department, often alleging universities haven't accurately reported on-campus crime or appropriately punished assailants as required under federal law.

A former Amherst College student, Angie Epifano, has accused the school of trivializing her report of being raped in a dorm room in 2011 by an acquaintance. She said school counselors questioned whether she was really raped, refused her request to change dorms, discouraged her from pressing charges and had police take her to a psychiatric ward. She withdrew from Amherst while her alleged attacker graduated.

Among the federal laws requiring colleges to address sexual assault are: Title IX, which prohibits gender discrimination in education; the renewed Violence Against Women Act Obama, which was signed into law last year with new provisions on college sexual assault; and the Clery Act, which requires colleges and universities to publicly report their crime statistics every year.

The Education Department has investigated and fined several schools for not accurately reporting crimes. Most notably was a 2006 case at Eastern Michigan University, in which the government eventually fined the school a then-record $357,000 for not revealing a student had been sexual assaulted and murdered in her dorm room.

Violent crime can be underreported on college campuses, advocates say, because of a university's public-image incentive to keep figures low, or because crimes can occur off campus and instead investigated by local police. Other times, schools put such suspects before a campus court whose proceedings are largely secret and not subjected to judicial review.

Students Active for Ending Rape, a nonprofit group that works with student activists to push for sexual assault policy changes on their campuses, said in a report last year that schools often do not fully address the problem.

The report gave more than 80 percent of college policies a grade C or below, an F to nearly one-quarter and said one-third don't fully comply with the Clery Act.

The White House report also declares that the criminal justice response to sexual assault broadly is too often inadequate and lays out a goal of increasing arrest, prosecution and conviction rates without any specific targets.

The report blames police bias and a lack of training to investigate and prosecute sex crimes for low arrest rates and says the federal government should promote training and help police increase testing of DNA evidence collected from victims.

The report mentions sexual assaults in the military -- Obama last month directed the Pentagon to better prevent and respond to the crime within its ranks or face further reforms. White House officials say they want to set the example by turning around the sexual assault problem in the military. "I've made it clear I expect significant progress in the year ahead," Obama said.