I will give Ohio some points, but why only retired LEOs?
I heard the gentleman who is suggesting this on the radio a couple of days ago.
Essentially, retired officers are already trained to handle firearms (and are much more responsible with them than "civilians") and it would be cheaper for them to get teaching certificates than it would be to train a regular teacher.
While I don't have a problem with the proposal, I do get tired of the "police are the only ones sufficiently trained to handle this firearm" stuff.
The other thing is that they were only suggesting using them as substitute teachers. While I am for armed teachers, I am just not sure from one day to the next you could count on random sub situations providing enough security.