What is up with that? Tazering kids?
I mean if the kid had a weapon, I can understand... but it better be a dangerous weapon that a full grown adult can't handle with less than a tazer.
"who was wielding a piece of glass "
Would you want to approach an out of control kid armed with broken glass? If the kid gets cut or hurt when you throw a blanket over him, you know you will be sued. If you get hurt, you are pretty much on your own. If you are a cop, why take the risk.