While the breadth of the problem is unclear, the Government Accountability Office noted there have been numerous media reports of such cases and referenced a 2004 Education Department report that estimated nearly 10 per cent of students are victims of sexual abuse by school personnel sometime during their school career.
One of the most high-profile sexual abuse cases was in Los Angeles, where a once-respected teacher was sentenced in November to 25 years in prison after entering the legal equivalent of guilty pleas to 23 counts of committing lewd acts on children.
In January alone, teachers have faced sex crime charges in Phoenix, Provo, Utah, and Elizabethtown, Ky., according to news reports.
The GAO, the investigative arm of Congress, challenged the departments of Education, Health and Human Services and Justice to do more.
"Although several federal agencies collect related data, none systematically identify the extent of sexual abuse by school personnel, and efforts to address this data gap are limited," the report said.
In response, Education Department official Deborah Delisle told the GAO "to the extent possible" the department will explore ways to better track the problem. She said the agency is updating its sexual misconduct training and will explore ways, "given available resources," to collaborate with the other agencies.
Rep. George Miller, D-Calif., who requested the GAO review, said the issue is often "treated as something that isn't discussed," but schools have a legal duty to keep students safe from such abuse and that includes a responsibility to ensure such cases don't happen. He's seeking congressional hearings on the issue.
"We know that it is a very real and serious problem and it's fairly prevalent throughout the nation's schools, in different degrees," said Miller, the minority leader of the House Education and Workforce Committee.
The report is a follow-up to a 2010 GAO report that explored 15 cases in which individuals with histories of sexual misconduct were hired or retained by public and private schools as teachers, support staff, volunteers and contractors. In some cases, districts knowingly passed a potential predator to another district, the GAO said. The House passed a bill last year that would create consistency across states in criminal history background check policy.
One issue the GAO focused on in the new report was "grooming" in which perpetrators get to know students or their families to first build trust. The growing use of technology and social media makes the issue particularly relevant, the report said. It said knowing early signs of such inappropriate behaviour can help stop sexual abuse before it happens, but that only 18 states require school districts to provide training on sexual abuse and misconduct.
In the report, the GAO highlighted five cases, including one in North Carolina in which a teacher was sentenced to prison time for indecent liberties following an allegation that the teacher had engaged in inappropriate touching of students. An investigation determined that the teacher had taken female students out to dinner and purchased gifts such as a necklace and camera.
Federal law establishes minimum standards for state mandatory reporting laws regarding known or suspected child abuse, but states primarily define the requirements, the GAO said. While most states have laws requiring school personnel to report sexual abuse, school districts may have their own policies that can sometimes create challenges, the agency found. It said, for example, that three districts it visited have policies requiring suspected abuse to be reported to school administrators.
"This can result in a failure to report to the proper law enforcement" or child protection authority, the report said.
Among the GAO's findings:
—Even though 46 states require criminal background checks of school employees, methods and sources used vary, with some state and employee group officials telling the GAO they have questioned the accuracy of the background checks.
—Forty-two states have professional standards or codes of conduct, and 22 of those included information on appropriate boundaries between personnel and students.
—While education regulations require schools to have procedures in place to protect students from sexual abuse by school personnel, many local school officials told the GAO they are unsure how to apply these requirements.