Hamilton City Schools has been cleared of any suspicion of improperly removing students from its attendance rolls, according to a final audit released Monday by the Ohio State Auditor Dave Yost

Yost said more than 260 auditors spent 10,807 billable hours investigating possible scrubbing in a sample of the state’s schools at a cost of $443,000. Yost said the audit looked at 331 individual schools in 137 districts and most Ohio schools are following the rules.

The investigation found nine districts statewide manipulated attendance data, including Cincinnati Public Schools and Winton Woods schools in Hamilton County.

The Hamilton City School District was found to have no evidence of scrubbing of attendance data.

“Auditors were in the district in September and October with district personnel, reviewing over 400 student files,” said district spokeswoman Joni Copas.

Hamilton was among 100 schools in 47 districts flagged by the state Department of Education for having “high mobility,” or a high number of students coming and going from the district, Copas said. Auditors spent about 11 days on-site in Hamilton during September, Copas said, before taking data and records off-site for further analysis.

The auditors were mostly concerned about records from Garfield Middle School and the now-closed Hamilton Education Center.

Copas said Hamilton’s high mobility can be attributed in part to the Butler County Juvenile Justice Center utilizing the Hamilton City School District to provide educational programming to residents being housed in both the Juvenile Rehabilitation Center and Juvenile Detention Center. Copas said the teachers offering those educational programs are employees of the Hamilton district.

“The district takes the responsibility of entering data very seriously and will follow recommendations suggested by the Ohio Department of Education,” Copas said.

Yost said the vast majority of Ohio schools followed the rules and doesn’t think state law and policy is unclear, but there were warning signs that could have been checked by the Ohio Department of Education. Yost recommended the state collect attendance data continually throughout the year, instead of during one week in October, to discourage tampering with data.

Yost forwarded the report to the U.S. Department of Education Inspector General. He said no referrals to county prosecutors have been made, but the investigation uncovered actions that warrant disciplinary action.

The audit did not make conclusions about motivation behind enrollment changes, which might have caused gains on school district report cards and other accountability measures.