(KFVS) - Most of the Heartland states received bad grades when it comes to hiring teachers.
A new investigation from USA Today found some teacher's work history may be falling through the cracks.
The study took more than a year, and sorted through each of the 50 states.
The news organization said their audit sparked three internal investigations so far.
The standards for hiring teachers varies from state to state.
If a teacher is disciplined in one state they could easily move to another state and leave that behind them.
There is a private database through The National Association of State Directors of Teacher Education and Certification; however, not all states choose to report the information.
USA Today found 9,000 teachers were not added to the list. Of those, 1,400 lost their licenses completely. Two hundred of those faced allegations of physical or sexual abuse.
USA Today gave each state their own report card.
Illinois and Kentucky got Cs.
The study said Illinois is better about reporting information, but their background checks are left to local school districts.
Missouri was below average with a D grade. It had strong background checks, but weak disciplinary reporting.
Tennessee flunked USA Today's test.
North Dakota is an example of a state who received high grades.
One Bollinger County, Missouri school official said they conduct comprehensive background checks, but that only covers convictions.