If the police took longer to react to this shooting and also the Garlic Festival shooting in California, the death toll could have been 20+ in both.
I think the Ohio shooting is one of the shortest ever, the shooter dead after just 30 seconds.
If he used all 250 rounds at the rate he was firing at Connor Betts could have killed 40+ people in around 3 minuets if it was not for the fast police response.