Nearly all campus police officers at public universities now carry guns, pepper spray and other weapons, according to a new Justice Department report, and experts say more private schools are looking to arm police.

Overall, about two-thirds of public and private campuses used armed officers during the 2011-12 school year, according to the Bureau of Justice Statistics survey of 900 four-year colleges with at least 2,500 students. Officers at public universities were more than twice as likely as those at private schools to carry guns.

Despite the increase, schools aren’t required to report weapon use to federal authorities.

Experts said campus administrators are increasingly pressed for assurances that officers are well-equipped and well-trained following high-profile crimes like the 2007 Virginia Tech shootings and the Penn State child sex abuse case.

“Compared to 10 years ago, we’ve made drastic improvements to become more professional, more accountable and more responsive to the expectation of our campus community,” said Florida State University Police Chief David Perry, who serves as president of the International Association of Campus Law Enforcement Administrators.

“Parents are asking up front ... do you have weapons, can you respond to an active shooter if there was a situation on your campus?” he said.

The Bureau of Justice Statistics last surveyed campus law enforcement agencies in 2004-05. On the more than 700 campuses questioned for both reports, the percentage of agencies arming their officers rose from 68 percent to 75 percent. About 32,000 people were working full-time for campus law enforcement at four-year institutions in 2011-12, the most recent statistics available.

About 92 percent of public campuses used sworn police officers, those with full arrest powers, and most sworn officers were authorized to carry guns, pepper spray and batons and to patrol beyond campus boundaries, the report said. About 40 percent could carry a stun gun.

Federal authorities don’t track how often weapons are used, the report’s author, BJS senior statistician Brian Reaves, said.

“There is no DOJ requirement for reporting the use of weapons by police,” Reaves said by email. “The individual agencies would likely have records of this, but DOJ does not attempt to collect this information as part of any systematic data collection.”

While only about 38 percent of private campuses relied on sworn officers in 2011-12, interest appears to be growing in full-service agencies that don’t have to rely on outside police for enforcement, said campus public safety expert Steven Healy, a former public safety director at Princeton University.

“It’s an evolution. Low probability, high-impact incidents like the violent situation at Virginia Tech obviously loom large in everyone’s thinking, but that’s not the only issue,” Healy said. “You have to consider all the threats and vulnerabilities and ultimately, what do you want from these people that you hire to protect and keep the campus safe. Are you looking for observe and report ... or do you want your own department to be able to respond to the full range of threats?”

Ohio State University police faced a chaotic scene last week when football fans swarmed the empty football stadium and partially frozen Mirror Lake, a popular student gathering spot, after their team’s victory in the NCAA football title game. Officers used pepper spray to disperse the crowds, who tore down a temporary goal post at the stadium.

“There was elevated concern revelers would get hurt or fall through the ice,” university spokesman Dan Hedman said. While officers made no arrests on campus, the investigation is ongoing, he said.

Law enforcement agencies at four-year schools with at least 2,500 students handled an average of five sexual assaults or other violent crimes in 2011, and 180 property crimes, including thefts and burglaries, according to the report, which cited data reported by colleges to the U.S. Department of Education under the federal Clery Act. The rate of violent crime was 27 percent lower in 2011 than in 2004, while the property crime rate dropped 35 percent, the report said.