At least 13 school bus drivers throughout Utah have criminal convictions that should disqualify them from the job and another 10 have highly questionable driving records, according to a legislative audit released Tuesday.

Ten drivers have serious moving violations such as a DUI or driving on a suspended license. The other 13 have been convicted of violent crimes such as domestic violence, child abuse/neglect, aggravated assault and negligent manslaughter, according to the audit.

In all, the audit looked at nearly 2,700 drivers in 36 of Utah's 40 districts and found 88 drivers, or 3 percent, had multiple tickets or serious violations on their records.

"First, some current bus drivers may not be considered safe drivers," the audit said. "Second, some bus drivers have criminal convictions on their records that should disqualify them from driving."

The drivers work in nine school districts throughout the state including Granite, Salt Lake City, Cache, Alpine, Davis, Jordan, Provo, Weber and Carbon. Auditors did not name the drivers, citing privacy concerns. But they said they did alert those districts employing the drivers in question.

Officials from several districts said Tuesday they weren't able to comment specifically about drivers found to have criminal convictions in the audit because they didn't have enough information. Auditors did not give districts the drivers' names.

The audit recommends the Utah Office of Education require stronger criminal background checks when hiring drivers and consider requiring districts to perform periodic criminal background checks on drivers after they are hired.

It also recommends the state office require districts to check driving records at least once a year after drivers are hired.

Now, districts do criminal background checks and motor vehicle record checks when hiring drivers. But once drivers are working, there is no requirement to perform criminal background checks again, and the requirements for re-checking driving records can be confusing.

In 2007, about 35 percent of Utah districts did not run annual checks of their drivers' motor vehicle records, according to the audit.

Murrell Martin, state pupil transportation specialist, said Tuesday night he planned to send a letter to all school districts asking them to make sure they've recently checked drivers' motor vehicle records and suggesting they move to a more stringent type of criminal background check.

Martin said his office agrees with the auditors' recommendations and a committee is working to address them. He said the committee hopes to finalize changes to state standards by March. His office recently also hired an instruction and certification specialist to make sure records are being tracked appropriately and to work on training issues.

It's a position that hadn't been filled for about five years, he said.

"We're anxious to make any improvements we can and always looking for ways to improve," Martin said.

Tom Given, Granite transportation director, said Granite already checks drivers' motor vehicle records every three months. Jordan checks them twice a year, said Jim Hinckle, Jordan transportation director. The Salt Lake City and Alpine school districts check vehicle records at least annually, officials from those districts said.

Many districts, however, don't routinely perform criminal background checks after hiring drivers. And some districts hire drivers even if they do have a criminal history.

Granite district spokesman Ben Horsley said the district has one driver, for example, who was charged with domestic violence, but the charge happened long ago and involved the man chest bumping his wife.

He said a district committee sometimes looks at situations on a case by case basis, although Granite would never hire someone convicted of child abuse or a sex offense.

Kelly Orton, Salt Lake director of support services, said performing regular criminal background checks on drivers, and all other employees for that matter, simply might not be realistic.

"That becomes a logistical and financial nightmare," Orton said. "It's a good thing. I just don't know if it's feasible."

Martin said it's an issue the state committee will likely tackle.

Though auditors found problems with some drivers' records, they also noted that school busing is still the safest means of transporting students to school, and "the busing of Utah children is done effectively."

The audit also looked at ways districts and the state can increase the cost efficiency of school buses and the reliability of data having to do with school transportation.