Prior GAO testimonies have described cases of physical abuse of children at youth residential treatment programs and public and private schools. However, children are also vulnerable to sexual abuse. A 2004 Department of Education report estimated that millions of students are subjected to sexual misconduct by a school employee at some time between kindergarten and the twelfth grade (K-12). GAO was asked to (1) examine the circumstances surrounding cases where K-12 schools hired or retained individuals with histories of sexual misconduct and determine the factors contributing to such employment actions and (2) provide an overview of selected federal and state laws related to the employment of convicted sex offenders in K-12 schools. To identify case studies, GAO compared 2007 to 2009 data employment databases from 19 states and the District of Columbia to data in the National Sex Offender Registry. GAO also searched public records from 2000 to 2010 to identify cases in which sexual misconduct by school employees ultimately resulted in a criminal conviction. GAO ultimately selected 15 cases from 11 states for further investigation. For each case, to the extent possible, GAO reviewed court documents and personnel files and also interviewed relevant school officials and law enforcement. GAO reviewed applicable federal and state laws related to the employment of sex offenders and requirements for conducting criminal history checks. The 15 cases GAO examined show that individuals with histories of sexual misconduct were hired or retained by public and private schools as teachers, support staff, volunteers, and contractors. At least 11 of these 15 cases involve offenders who previously targeted children. Even more disturbing, in at least 6 cases, offenders used their new positions as school employees or volunteers to abuse more children. GAO found that the following factors contributed to hiring or retention: (1) school officials allowed teachers who had engaged in sexual misconduct toward students to resign rather than face disciplinary action, often providing subsequent employers with positive references; (2) schools did not perform preemployment criminal history checks; (3) even if schools did perform these checks, they may have been inadequate in that they were not national, fingerprint-based, or recurring; and (4) schools failed to inquire into troubling information regarding criminal histories on employment applications. GAO found no federal laws regulating the employment of sex offenders in public or private schools and widely divergent laws at the state level. For example, some states require a national, fingerprint-based criminal history check for school employment, while others do not. State laws also vary as to whether past convictions must result in termination from school employment, revocation of a teaching license, or refusal to hire.