IL- Child molesting teacher worked at another school

The seemingly expanding case of a child molesting teacher, Harold Jerry Mash, is deeply troubling.  

Most laws requiring background checks for teachers went into effect in the 1990s. Yet in 1998, Mash predictably and successfully hid his criminal past from school officials who apparently failed to do a thorough background check to ensure the safety of kids.

Mash omits on his resume Rossford public schools altogether, and instead lengthens his time with Toledo Public schools. Why?  We suspect it's because he had a criminal conviction for the abuse of a juvenile that was well established with the professionals at Rossford school district and the courts where he was criminally convicted for the sexual molestation of a 14 year old boy.

Mash omits on his resume that he was in Davenport, Iowa and instead says on his resume he was in Pittsburgh, PA. Why?  We suspect it's because there was another criminal conviction for assault and battery, this time of a woman. 

We expect child predators to lie, omit and blatantly say one thing but do another. What's inexcusable is for school officials to embolden and hire such criminals, enabling them to get a teaching license which essentially becomes a license to prey.

Had the State of Illinois acted responsibly, maybe Mash would have been denied a license, because a simple background check and employment check would have yielded multiple criminal convictions and arrests.

Had the Ohio Department of Education acted responsibly, when Mash applied in 1987 for his teaching license, perhaps they would have learned of the 1986 conviction and the 1976 convictions?

Had Palmer College in Davenport, Iowa acted responsibly, maybe they would have seen that Mash was criminally convicted a year earlier in Davenport for assaulting a woman in 1986?

Had Rossford public schools acted responsibly, maybe Mash would never have had a license to prey in Pittsburgh, Davenport, Chicago, or Maywood?

Had Toledo public schools done its job, maybe he would never have gotten to Rossford public schools and John Doe - and others - would never have been criminally assaulted by Mash. 

With all these resources at the disposal of all of these institutions, whose charge even above educating youth, is to protect kids, why did none of them do the right thing?

There are several educational institutions involved here. They all get an A for their role in “passing the trash.” They get an F for protecting kids.