A little kindergartener in my tutoring group tried to cut his friend. With scissors. While I was working with another little boy. This is not normal Kindergarten behavior.
If he's not kicking someone or flicking markers, glue caps, or erasers at other students, he's threatening them. There is no impulse control.
The last time I saw a situation like this, I was working with Fetal Alcohol Syndrome affected children. I'm seriously worried about him.
We're taking him out of a group situation and I'm going to start working with him one-on-one. I lose out on some of my planning time, but I think this is more important. He can't work in a group---the others are suffering. We just can't get anything done. This way, the others get to learn without wondering if they're going to bear the brunt of his impulses that day, and he gets the one-on-one help he so desperately needs.